Chemical Reactions and Equations

Front

What type of change occurs when wood burns to form ashes and gases?

Back

Chemical change.

Front

What does the Law of Conservation of Mass state?

Back

Mass can neither be created nor destroyed, it can only change form.

Front

What is the chemical formula for methane?

Back

CH₄.

Front

What type of chemical reaction releases thermal energy?

Back

Exothermic reaction.

Front

What type of reaction absorbs thermal energy from the environment?

Back

Endothermic reaction.

Front

What is a reactant in a chemical reaction?

Back

A substance that undergoes change during a chemical reaction.

Front

What is a product in a chemical reaction?

Back

A substance that is formed as a result of a chemical reaction.

Front

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

Back

A physical change alters the form of a substance without changing its identity, while a chemical change results in the formation of new substances.

Front

What is an example of an exothermic reaction?

Back

Combustion of fuels, such as burning wood or gasoline.

Front

What is an example of an endothermic reaction?

Back

Photosynthesis, where plants absorb energy from sunlight.