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BÀI ÔN TẬP RÈN LUYỆN LÝ THUYẾT TỔNG HỢP MÔN HÓA HỌC (P3)

Cho các chất sau: axetilen, phenol, glucozơ, toluen, isopren, axit acrylic, axit oleic, etanol, anilin. Số chất làm mất màu nước brom ở điều kiện thường là

Hóa học Tốt nghiệp THPT
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Bài tập về Este - Lipit cực hay có lời giải chi tiết (P1)

Đun nóng m gam chất hữu cơ X (chứa C, H, O và có mạch cacbon không phân nhánh) với 100 ml dung dịch NaOH 2M đến phản ứng hoàn toàn. Để trung hòa lượng NaOH dư cần 40 ml dung dịch HCl 1M. Cô cạn dung dịch sau khi trung hòa thu được 7,36 gam hỗn hợp hai ancol đơn chức (Y), (Z) và 15,14 gam hỗn hợp hai muối khan, trong đó có một muối của axit cacboxylic (T). Phát biểu nào sau đây đúng?

Hóa học Lớp 12
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word(s) for each of the following blanks.Stress      Stress is important. We all need a certain amount of it in order to (46) x fulfilling lives. However, if we have too much of it, it can have the opposite effect. Some people can tolerate greater (47) x of stress than others, but most of us will (48) x at some time in our lives. It is, (49) x , a good idea to learn a few stress management techniques. Identifying the cause of the problem we have, so that we can (50) x it more effectively, is one of the first step towards reducing stress.The second is talking to a person you can trust, who will listen and, if necessary, give you some positiveadvice. Not only are smoking and drinking (51) x to our health, they actually increase stress (52) x than reduce it. So, next time you want to relax, instead of reaching for that glass of wine or a cigarette, have a warm bath or go for a walk. Walking has more than health (53) x . It helps you think more clearly, (54) x . Pets have calming influences on us, unless they make noise which irritates us. In fact, unwanted noises should be avoided as far as possible. On the other hand, laughter is one of the best ways to make yourself feel (55) x better.Question 48

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word(s) for each of the following blanks.Stress      Stress is important. We all need a certain amount of it in order to (46) x fulfilling lives. However, if we have too much of it, it can have the opposite effect. Some people can tolerate greater (47) x of stress than others, but most of us will (48) x at some time in our lives. It is, (49) x , a good idea to learn a few stress management techniques. Identifying the cause of the problem we have, so that we can (50) x it more effectively, is one of the first step towards reducing stress.The second is talking to a person you can trust, who will listen and, if necessary, give you some positiveadvice. Not only are smoking and drinking (51) x to our health, they actually increase stress (52) x than reduce it. So, next time you want to relax, instead of reaching for that glass of wine or a cigarette, have a warm bath or go for a walk. Walking has more than health (53) x . It helps you think more clearly, (54) x . Pets have calming influences on us, unless they make noise which irritates us. In fact, unwanted noises should be avoided as far as possible. On the other hand, laughter is one of the best ways to make yourself feel (55) x better.Question 47

Tiếng Anh Tốt nghiệp THPT
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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Hợp chất nào sau đây không phản ứng với Al2O3 ngay cảở nhiệt độ cao?

Hóa học Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word(s) for each of the following blanks.Stress      Stress is important. We all need a certain amount of it in order to (46) x fulfilling lives. However, if we have too much of it, it can have the opposite effect. Some people can tolerate greater (47) x of stress than others, but most of us will (48) x at some time in our lives. It is, (49) x , a good idea to learn a few stress management techniques. Identifying the cause of the problem we have, so that we can (50) x it more effectively, is one of the first step towards reducing stress.The second is talking to a person you can trust, who will listen and, if necessary, give you some positiveadvice. Not only are smoking and drinking (51) x to our health, they actually increase stress (52) x than reduce it. So, next time you want to relax, instead of reaching for that glass of wine or a cigarette, have a warm bath or go for a walk. Walking has more than health (53) x . It helps you think more clearly, (54) x . Pets have calming influences on us, unless they make noise which irritates us. In fact, unwanted noises should be avoided as far as possible. On the other hand, laughter is one of the best ways to make yourself feel (55) x better.Question 46

Tiếng Anh Tốt nghiệp THPT
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BÀI ÔN TẬP RÈN LUYỆN LÝ THUYẾT TỔNG HỢP MÔN HÓA HỌC (P3)

Cho dãy các chất: CH4, C2H2, C2H4, C2H5OH, CH2=CH-COOH, C6H5NH2 (anilin), C6H5OH (phenol), C6H6 (benzen). Số chất trong dãy phản ứng được với nước brom là:

Hóa học Tốt nghiệp THPT
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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Cho dãy các chất: Cu, CuO, Fe3O4, C, FeCO3, Fe(OH)3. Số chất trong dãy tác dụng với H2SO4 đặc, nóng, dư không tạo khí SO2 là

Hóa học Tốt nghiệp THPT
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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Thuốc thử nào dưới đây phân biệt được khí O2 và O3 bằng phương pháp hóa học?

Hóa học Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories.   In the last paragraph, what does the author imply is a major function of hypotheses ?

Tiếng Anh Tốt nghiệp THPT
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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Cho 26,88 gam bột sắt vào 600 ml dung dịch hỗn hợp A gồm Cu(NO3)2 0,4M và NaHSO4 1,2M. Sau khi các phản ứng xảy ra hoàn toàn thu được m gam chất rắn B và khí NO( sản phản khử duy nhất ở đktc). Giá trị của m là

Hóa học Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. In the last paragraph, what does the author imply is a major function of hypotheses ?

Tiếng Anh Tốt nghiệp THPT
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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Cho m gam hỗn hợp X gồm Ba, BaO, Al vào nước dư phản ứng kết thúc được dung dịch Y; 3,024 lít khí (đktc) và 0,54 gam chất rắn không tan. Rót 110 ml dung dịch HCl 1M vào dung dịch Y được 5,46 gam kết tủa. Giá trị của m là

Hóa học Tốt nghiệp THPT
Xem chi tiết 299 lượt xem 6 năm trước
Bài tập về Este - Lipit cực hay có lời giải chi tiết (P1)

Đốt cháy hoàn toàn 3,4 gam hợp chất hữu cơ X (phân tử chỉ chứa một loại nhóm chức), cho toàn bộ sản phẩm cháy vào bình đựng dung dịch Ca(OH)2 dư thấy xuất hiện 16 gam kết tủa trắng đồng thời khối lượng dung dịch giảm 7,16 gam. Đun nóng 34 gam X trong 500 ml dung dịch NaOH 1M thấy tạo thành chất hữu cơ Y. Phần dung dịch còn lại đem cô cạn thu được 41,6gam chất rắn, trong đó có một muối natri của axit hữu cơ đơn chức. Chất Y phản ứng với Cu(OH)2 cho dung dịch xanh lam. Cho tỉ khối hơi của X so với khí H2 là 85 (ở cùng điều kiện). Các phản ứng hóa học đều xảy ra hoàn toàn. Khẳng định nào sau đây là đúng?

Hóa học Lớp 12
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. In paragraph 4, the author refers to a hypothesis as "a leap into the unknown” in order to show that hypotheses x

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. In the fourth paragraph, the author implies that imagination is most important to scientists when they x

Tiếng Anh Tốt nghiệp THPT
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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Chất có nhiệt độ sôi cao nhất là

Hóa học Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. “Bricks” are mentioned in paragraph 3 to indicate how x

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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Hòa tan hoàn toàn 11,2 gam CaO và H2O thu được dung dịch A. Sục khí CO2 vào dung dịch A, qua quá trình khảo sát người ta lập đồ thị của phản ứng như sau:      KL kết tủa                         x                15x                  Số mol CO2   Giá trị của X là

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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. The word "supported" in paragraph 2 is closest in meaning to x

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. According to the second paragraph, a useful theory is one that helps scientists to x

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Đề thi thử THPT Quốc gia năm 2019 Hóa học có lời giải (Đề số 30)

Trong các polime sau: polietilen, tơ nitron, xenlulozơ, poli(vinyl clorua), tơ nilon-6,6, có bao nhiêu polime là sản phẩm của phản ứng trùng hợp?

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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. The word "this" in paragraph 1 refers to x

Tiếng Anh Tốt nghiệp THPT
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Tổng hợp đề thi Tiếng Anh có lời giải (Đề số 5)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observation, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists' predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hyphthesis is a leap into the unknown.It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. The word "related" in paragraph 1 is closest in meaning to x

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Đề thi thử THPT Quốc gia năm 2019 Hóa học có lời giải (Đề số 30)

Cho sơ đồ chuyển hóa sau: Tinh bột → X → Y → Axit axetic. Chất X và chất Y lần lượt là

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20 đề thi thử THPTQG môn Sinh học năm 2019 - 2020 (Đề số 3)

Ruồi giấm bộ NST 2n = 8. Trên mỗi cặp NST thường xét 2 cặp gen dị hợp, trên cặp NST giới tính xét 2 locut gen trên vùng tương đồng của X và Y. Biết không có đột biến xảy ra. Một cá thể ruồi giấm đực có kiểu gen dị hợp về các gen đang xét cho số loại tinh trùng tối đa là

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Đề thi thử THPT Quốc gia năm 2019 Hóa học có lời giải (Đề số 30)

Cho phản ứng hóa học: KOH + HCl → KCl + H2O. Phản ứng nào sau đây có cùng phương trình ion thu gọn với phản ứng trên?

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20 đề thi thử THPTQG môn Sinh học năm 2019 - 2020 (Đề số 3)

Ở một loài thực vật, tính trạng khối lượng quả do nhiều cặp gen quy định nằm trên các cặp NST khác nhau di truyền theo kiểu tương tác cộng gộp. Cho cây có quả nặng nhất 120g lai với cây có quả nhẹ nhất 60g được F1. Cho F1 giao phấn tự do được F2 có 7 loại kiểu hình về tính trạng khối lượng quả. Ở F2, loại cây có quả nặng 90g chiếm tỉ lệ

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Bài 6: Tính chất của hai tiếp tuyến cắt nhau

Cho góc xAy khác góc bẹt, điểm B thuộc tia Ax. Hãy dựng đường tròn (O) tiếp xúc với Ax tại B và tiếp xúc với Ay.

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282 Bài tập Đại cương về kim loại cực hay có lời giải (P7)

Điện phân dung dịch chứa 53,9 gam hỗn hợp muối NaCl và Cu(NO3)2 với điện cực trơ, màng ngăn xốp, đến khi nước điện phân ở cả hai điện cực thì ngừng điện phân, tại thời điểm này thể tích khí sinh ở anot gấp 1,5 lần thể tích khí thoát ra ở catot ở cùng điều kiện nhiệt độ và áp suất. Nhận xét nào sau đây không đúng?

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Đề thi thử THPT Quốc gia năm 2019 Hóa học có lời giải (Đề số 30)

Polime có cấu trúc mạch phân nhánh là

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Bài 6: Tính chất của hai tiếp tuyến cắt nhau

Cho góc xAy khác góc bẹt. Tâm của các đường tròn tiếp xúc với hai cạnh của góc xAy nằm trên đường nào?

Toán Lớp 9
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Bài 6: Tính chất của hai tiếp tuyến cắt nhau

Từ một điểm A nằm bên ngoài đường tròn (O), kẻ các tiếp tuyến AB, AC với đường tròn (B, C là các tiếp điểm). Qua điểm M thuộc cung nhỏ BC, kẻ tiếp tuyến với đường tròn (O), nó cắt các tiếp tuyến AB và AC theo thứ tự ở D và E. Chứng minh rằng chu vi tam giác ADE bằng 2AB.  

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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Sản phẩm của phản ứng nhiệt phân hoàn toàn KNO3 là

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20 đề thi thử THPTQG môn Sinh học năm 2019 - 2020 (Đề số 3)

Ở bò, gen A nằm trên NST thường quy định chân cao trội hoàn toàn so với a quy định chân thấp. Trong một trại chăn nuôi có 20 con đực giống chân cao và 200 con cái chân thấp. Quá trình ngẫu phối đã sinh ra đời con có 80% cá thể chân cao, 20% cá thể chân thấp. Trong số 15 con bò đực trên, có bao nhiêu con có kiểu gen dị hợp?

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Bài tập về Este - Lipit cực hay có lời giải chi tiết (P1)

X là este của axit A và ancol đơn chức B. Đun nóng 32,34 g X với dung dịch NaOH dư đến khi phản ứng hoàn toàn. Cô cạn dung dịch thu được chất rắn Y và ancol B. Đun ancol B với H2SO4 đặc thu được 12,0736 lít khí Z ở 27,3°C, 1 atm và dZ/B = 0,609. Nung Y với vôi tôi xút thu được 5,488 lít khí T duy nhất có tỉ khối so với hiđro bằng 8. Công thức cấu tạo của X là:

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Bài tập về Este - Lipit cực hay có lời giải chi tiết (P1)

Xà phòng hoá 3,52 gam este X được tạo ra từ axit đơn chức và ancol đơn chức bằng dung dịch NaOH vừa đủ được muối Y và ancol Z. Nung nóng Y với oxi thu được 2,12 gam Natri cacbonat, khí CO2 và hơi nước. Ancol Z  được chia làm hai phần bằng nhau. Phần 1 cho tác dụng với Na vừa đủ thu được khí H2 có số mol bằng 1/2 số mol ancol phản ứng và 1,36 gam muối. Phần 2 cho tác dụng với CuO dư, nung nóng được chất hữu cơ T có phản ứng tráng bạc. Công thức cấu tạo của X là:

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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Khí G được dùng đểkhử trùng cho nước sinh hoạt. Khí G là

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20 đề thi thử THPTQG môn Sinh học năm 2019 - 2020 (Đề số 3)

Khi lai cà chua quả màu đỏ, dạng tròn với cà chua quả màu vàng, dạng bầu dục ở F1 thu được 100% quả màu đỏ, dạng tròn. Cho F1 tự thụ phấn thu được F2 tổng số 150 cây, trong đó có 99 cây quả màu đỏ, dạng tròn. Cho rằng mỗi gen quy định một tính trạng, không có đột biến xảy ra, mọi diễn biến của quá trình sinh giao tử đực và cái giống nhau. Tần số hoán vị gen là

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Đề thi thử THPT Quốc gia năm 2019 Hóa học có lời giải (Đề số 30)

Khi đốt than trong phòng kín sinh ra khí độc nào?

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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Hỗn hợp X gồm metan,propan, etilen, buten có tổng số mol là 0,57 mol tổng khối lượng là m. Đốt cháy hoàn toàn m gam X cần vừa đủ 54,88 lít O2(đktc).Mặt khác cho m gam X qua dung dịch Br2 dư thì thấy số mol Br2 phản ứng là 0,35 mol. Giá trị của m là:

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282 Bài tập Đại cương về kim loại cực hay có lời giải (P6)

Điện phân dung dịch X gồm FeCl2 và MgCl2 (có màng ngăn), sự phụ thuộc khối lượng của dung dịch X theo thời gian được biểu diễn theo đồ thị sau: Giá trị x là

Hóa học Lớp 12
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282 Bài tập Đại cương về kim loại cực hay có lời giải (P7)

Tiến hành điện phân dung dịch chứa NaCl 0,4M và Cu(NO3)2 0,5M bằng điện cực trơ, màng ngăn xốp với cường độ dòng điện không đổi I = 5A trong thời gian 8492 giây thì dừng điện phân, ở anot thoát ra 3,36 lít khí (đktc). Cho m gam bột Fe vào dung dịch sau điện phân, kết thúc phản ứng, thấy khí NO thoát ra (sản phẩm khử duy nhất của N+5) và 0,8m gam rắn không tan. Giá trị của m là

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Đề Ôn thi THPTQG 2019 Hóa Học cơ bản, nâng cao có lời giải chi tiết (P12)

Dung dịch axit nào sau đây được dùng trong ngành khắc chữ trên thủy tinh?

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Al2O3 tan được trong dung dịch nào sau đây?

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Điểm khác nhau cơ bản của hệ sinh thái nhân tạo so với hệ sinh thái tự nhiên là ở chỗ:

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Bài 6: Tính chất của hai tiếp tuyến cắt nhau

Cho đường tròn (O), điểm A nằm bên ngoài đường tròn. Kẻ các tiếp tuyến AB, AC với đường tròn (B, C là các tiếp điểm). Tính độ dài các cạnh của tam giác ABC; biết OB = 2cm, OA = 4cm

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Trong quan hệ hỗ trợ cùng loài, sự quần tụ giúp cho sinh vật: (1) Dễ dàng săn mồi và chống được kẻ thù hơn. (2) Hình thành các vùng lãnh thổ khác nhau của từng cặp trong đàn. (3) Dễ kết cặp trong mùa sinh sản. (4) Chống chọi với điều kiện bất lợi của tự nhiên. (5) Thúc đẩy quá trình chọn lọc tự nhiên. Phương án đúng là:

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Tiến hành điện phân dung dịch chứa Cu(NO3)2 1,2M và NaCl 0,8M bằng điện cực trơ, đến khi khối lượng dung dịch giảm 10,2 gam thì dừng điện phân. Cho 0,2 mol bột Fe vào dung dịch sau điện phân, kết thúc phản ứng, thấy thoát ra 0,672 lít khí NO (sản phẩm khử duy nhất, đktc) và còn lại m gam rắn không tan. Giá trị của m là

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Quặng nào sau đây giàu sắt nhất?

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