Chemistry Unit Review

Front

What is a pure substance?

Back

A pure substance is a material that has a constant composition and consistent properties throughout. Examples include elements and compounds.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together.

Front

What is a molecule?

Back

A molecule is the smallest unit of a chemical compound that retains its chemical properties, consisting of two or more atoms bonded together.

Front

What is the chemical formula for water?

Back

H2O, which indicates that each molecule of water is made up of two hydrogen atoms and one oxygen atom.

Front

What is the chemical formula for nitrogen gas?

Back

N2, which indicates that nitrogen gas is made up of two nitrogen atoms bonded together.

Front

What is an endothermic reaction?

Back

An endothermic reaction is a chemical reaction that absorbs heat from its surroundings, resulting in a decrease in temperature.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases heat, resulting in an increase in temperature.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance that cannot be broken down into simpler substances, while a compound is made up of two or more different elements chemically bonded together.

Front

What is the significance of chemical formulas?

Back

Chemical formulas provide a way to represent the composition of a substance, indicating the types and numbers of atoms present.

Front

What is the role of a chemist?

Back

A chemist studies the properties, composition, and reactions of substances to understand and manipulate chemical processes.