What Is Chemistry?

Chemistry, a branch of physical science, is the study of matter, physical and chemical properties of matter, and chemical reactions. Chemistry looks at why substances react with each other, and what the products of the reaction are. It looks at how chemical reactions occur all around us, and even inside of us.

Physical and Chemical Changes

There are two types of changes that a substance can go through: physical and chemical. A physical change may alter the appearance, shape, or size of a reactant, but no new substance is created. For example, freezing water is a physical change because while water does change into solid form, it retains its chemical formula and is the same substance. No new substance is created by freezing water.

A chemical change occurs because of a chemical reaction. A chemical change is a reaction between two or more substances that causes a completely different substance to be formed. For example, when iron and oxygen react with each other, they form rust. Rust is a completely different substance with a different chemical formula.

The Branches of Chemistry

There are 5 main branches of chemistry: analytical chemistry, physical chemistry, organic chemistry, inorganic chemistry, and biochemistry. Each of these branches look at different forms of matter and different chemical reactions.

Analytical Chemistry

Analytical chemistry uses quantitative(data from numbers) and qualitative(data from physical observations) data to measure the different properties of a substance.

Physical Chemistry

Physical chemistry uses physics to understand how matter and energy interact with each other to create different reactions.

Organic Chemistry

Organic chemistry studies chemical reactions that contain the element carbon. The properties of carbon allow it to form complex molecules. Carbon molecules make up most of the molecules and biomolecules in living organisms.

Inorganic Chemistry

Inorganic chemistry studies elements and compounds that do not have carbon atoms in them, such as metals, alloys, and gasses.

Biochemistry

Biochemistry studies the chemical reactions and processes that occur in living organisms, such as photosynthesis and cellular respiration.