Wednesday, 31 January 2018
Chemists study matter and the changes it undergoes. The substances that make up matter have unique physical properties that can be observed without changing their identity and unique chemical properties that, when they are demonstrated, do change the identity of the substances. Mixtures, whether homogeneous or heterogeneous, can be separated into pure components by physical means.
The scientific method
A scientific method is a systematic approach to research that begins with the gathering of information through observations and measurements. In the process, hypotheses, laws, and theories are devised and tested.
The study of chemistry involves three basic steps:
- Observations.
- Representations
- Interpretaions.
Representation involves the use of shorthand notation symbols and equations for communication.
Interpretations are based on atoms and molecules which is belong to the microscopic world.
Tuesday, 30 January 2018
Explain what is meant by the scientific method?
All sciences, including the social sciences, employ variations of what is called the scientific method, a systematic approach to research.
For example, a psychologist who wants to know how noise affects people's ability to learn chemistry and a chemist interested in measuring the heat given off when hydrogen gas burns in the air would follow roughly the same procedure in carrying out their investigations.
The first step is to carefully define the problem.
The next step includes performing experiments, making careful observations, and recording investigation.
The data obtained in a research study may be both qualitative (consisting of general observations about the system) and quantitative (comprising numbers obtained by various measurements of the system).
Chemists generally use standardized symbols and equations recording their measurements and observations. This form of representation not only simplifies the process of keeping records but also provides a common basis for communication with other chemists.
When the experiments have been completed and the data have been recorded, the next step in the scientific method is interpretation, meaning that the scientist attempts to explain the observed phenomenon. Based on the data that were gathered, the researcher formulates a hypothesis ( a tentative explanation for a set of observations). Further experiments are devised to test the validity of the hypothesis in as many ways as possible, and the process begins anew.
After a large amount of data has been collected, it is often desirable to summarize the information in a concise way, as a law.
In science, a law is a concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions.
For example, Sir Isaac Newton's second law of motion, which you may familiar, says that the force equals mass times acceleration ( F=ma). What this law means increases the mass or in the acceleration of objects will always increase its force proportionally, and a decrease in mass or acceleration will always decrease the force.
Hypotheses that survive many experimental tests of their validity may evolve into theories. A theory is a unifying principle that explains a body of facts and/or those laws that are based on them. Theories too are constantly being tested. If a theory is disproved by experiment, then it must be discarded or modified so that it becomes consistent with experimental observations. Proving or disproving a theory can take years, even centuries, in part because the necessary technology may not be available.
Scientific progress is seldom if ever, made in a rigid, step by step fashion. Sometimes a law precedes a theory, sometimes it is the other way around. Two scientists may start working on a project with exactly the same objective but will end up taking drastically different approaches. Scientists are after all human beings and their modes of thinking and working are very much influenced by their background, training, and personalities.
The development of science has been irregular and sometimes even illogical. Great discoveries are usually the result of the cumulative contributions and experience of many workers, even though the credit for formulating a theory or a law us usually given to only one individual. There is, of course, an element of luck involved in scientific discoveries but it has been said that "chance favors that prepared mind". It takes an alert and well-trained person to recognize the significance of an accidental discovery and to take full advantage of it. More often than not, the public learns only of spectacular scientific breakthroughs. For every success story, however, there are hundreds of cases in which scientists have spent years working on projects that ultimately led to the dead end, and in which positive achievements came only after many wrong turns and at such a slow pace that they went unheralded. Yet even dead ends contribute something to the continually growing body of knowledge about the physical universe. It is the love of search that keeps many scientists in the laboratory.
For example, a psychologist who wants to know how noise affects people's ability to learn chemistry and a chemist interested in measuring the heat given off when hydrogen gas burns in the air would follow roughly the same procedure in carrying out their investigations.
The first step is to carefully define the problem.
The next step includes performing experiments, making careful observations, and recording investigation.
The data obtained in a research study may be both qualitative (consisting of general observations about the system) and quantitative (comprising numbers obtained by various measurements of the system).
Chemists generally use standardized symbols and equations recording their measurements and observations. This form of representation not only simplifies the process of keeping records but also provides a common basis for communication with other chemists.
When the experiments have been completed and the data have been recorded, the next step in the scientific method is interpretation, meaning that the scientist attempts to explain the observed phenomenon. Based on the data that were gathered, the researcher formulates a hypothesis ( a tentative explanation for a set of observations). Further experiments are devised to test the validity of the hypothesis in as many ways as possible, and the process begins anew.
After a large amount of data has been collected, it is often desirable to summarize the information in a concise way, as a law.
In science, a law is a concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions.
For example, Sir Isaac Newton's second law of motion, which you may familiar, says that the force equals mass times acceleration ( F=ma). What this law means increases the mass or in the acceleration of objects will always increase its force proportionally, and a decrease in mass or acceleration will always decrease the force.
Hypotheses that survive many experimental tests of their validity may evolve into theories. A theory is a unifying principle that explains a body of facts and/or those laws that are based on them. Theories too are constantly being tested. If a theory is disproved by experiment, then it must be discarded or modified so that it becomes consistent with experimental observations. Proving or disproving a theory can take years, even centuries, in part because the necessary technology may not be available.
Scientific progress is seldom if ever, made in a rigid, step by step fashion. Sometimes a law precedes a theory, sometimes it is the other way around. Two scientists may start working on a project with exactly the same objective but will end up taking drastically different approaches. Scientists are after all human beings and their modes of thinking and working are very much influenced by their background, training, and personalities.
The development of science has been irregular and sometimes even illogical. Great discoveries are usually the result of the cumulative contributions and experience of many workers, even though the credit for formulating a theory or a law us usually given to only one individual. There is, of course, an element of luck involved in scientific discoveries but it has been said that "chance favors that prepared mind". It takes an alert and well-trained person to recognize the significance of an accidental discovery and to take full advantage of it. More often than not, the public learns only of spectacular scientific breakthroughs. For every success story, however, there are hundreds of cases in which scientists have spent years working on projects that ultimately led to the dead end, and in which positive achievements came only after many wrong turns and at such a slow pace that they went unheralded. Yet even dead ends contribute something to the continually growing body of knowledge about the physical universe. It is the love of search that keeps many scientists in the laboratory.
Chemistry: A science for the Twenty-First Century
Chemistry is the study of matter and the changes it undergoes.
Chemistry is often called the central science because a basic knowledge of chemistry is essential for students of biology, physics, geology, ecology and many other subjects. Indeed, it is central to our way of life, without it, we would be living shorter lives in what we would consider primitive conditions which are without automobiles, electricity, computers, CDs and many other everyday conveniences.
Although chemistry is an ancient science, its modern foundation was laid in the nineteenth century, when intellectual and technological advances enabled scientists to break down substances into ever smaller components and consequently to explain many of their physical and chemical characteristics. the rapid development of increasingly sophisticated technology throughout the twentieth century has given us even greater means to study things that cannot be seen with naked eye. Using computers and special microscopes. For example, chemists can analyze the structure of atoms and molecules. The fundamental units on which the study of chemistry is based and design new substances with specific properties, such as drugs and environmentally friendly consumer products.
It is fitting to ask what part the central science will have in the twenty-first century. Almost certainly chemistry will continue to play a pivotal role in all areas of science and technology.
Chemistry is often called the central science because a basic knowledge of chemistry is essential for students of biology, physics, geology, ecology and many other subjects. Indeed, it is central to our way of life, without it, we would be living shorter lives in what we would consider primitive conditions which are without automobiles, electricity, computers, CDs and many other everyday conveniences.
Although chemistry is an ancient science, its modern foundation was laid in the nineteenth century, when intellectual and technological advances enabled scientists to break down substances into ever smaller components and consequently to explain many of their physical and chemical characteristics. the rapid development of increasingly sophisticated technology throughout the twentieth century has given us even greater means to study things that cannot be seen with naked eye. Using computers and special microscopes. For example, chemists can analyze the structure of atoms and molecules. The fundamental units on which the study of chemistry is based and design new substances with specific properties, such as drugs and environmentally friendly consumer products.
It is fitting to ask what part the central science will have in the twenty-first century. Almost certainly chemistry will continue to play a pivotal role in all areas of science and technology.
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