CHEM – 1405 CHAPTER 1a
INTRODUCTION TO CHEMISTRY
CHEMISTRY
The branch of science that studies the composition of matter and its properties
Alchemy is a pseudoscience introduced by the Arabs in the 18th century.
Branches of chemistry
Inorganic Chemistry is the branch of chemistry that deals with the study those compounds where
carbon is not a major compound.
Organic chemistry is the branch of chemistry that deals with the study of Carbon compounds and
their derivatives.
Biochemistry is the branch of chemistry that studies the substances derived from plants and
animals.
Scientific Method
It is a systematic investigation of nature and requires proposing an explanation for the results of an
experiment in the form of a principle.
Hypothesis
A tentative proposal of a scientific principle is called a Hypothesis.
Theory
A hypothesis, which has sufficient evidence established through experiments, is called a Scientific
Theory. A theory explains the behavior of nature.
Law
A natural law does not explain the behavior, but gives a measurable relationship.
Consider the case when we drop ice into water,
Transfer of heat takes place from hotter objects to cooler one. This is a law because we can measure
experimentally the change in temperature.
Transfer of heat is due to the movement of molecules of ice and water. This is a theory.