Chemistry Unit Review

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include rusting, burning, and cooking.

Front

Which of the following is a physical change: Iron rusting, Sugar dissolving, or Eggs cooking?

Back

Sugar dissolving is a physical change.

Front

What is the Law of Conservation of Mass?

Back

The Law of Conservation of Mass states that mass cannot be created or destroyed in a chemical reaction.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a chemical reaction that releases energy, usually in the form of heat.

Front

What is an endothermic reaction?

Back

An endothermic reaction is a chemical reaction that absorbs energy from its surroundings.

Front

How many neutrons does an Oxygen atom have?

Back

An Oxygen atom has 8 neutrons.

Front

What is the difference between a physical and a chemical change?

Back

A physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.

Front

What happens to the mass of reactants in a chemical reaction?

Back

The mass of the reactants is equal to the mass of the products, according to the Law of Conservation of Mass.

Front

What is a mixture?

Back

A mixture is a combination of two or more substances that are not chemically bonded and can be separated by physical means.