Chemical Reactions Flashcard

Front

What is a chemical reaction?

Back

A change in substances to become new substances—molecules break apart and their atoms rearrange to form new substances.

Front

In a chemical reaction, are new types of atoms created?

Back

No, no new types of atoms are created, and no atoms are destroyed.

Front

What are reactants in a chemical reaction?

Back

The starting substances that undergo change, such as calcium chloride and sodium bicarbonate.

Front

What does it mean if a model of a chemical reaction shows the correct number of atoms in reactants and products?

Back

It means the law of conservation of mass is being followed.

Front

What is an example of a physical change?

Back

Thermal energy is added to water molecules, increasing their movement.

Front

What is the law of conservation of mass?

Back

Mass is neither created nor destroyed in a chemical reaction.

Front

What are products in a chemical reaction?

Back

The substances formed as a result of a chemical reaction.

Front

What is a catalyst?

Back

A substance that speeds up a chemical reaction without being consumed.

Front

What is an exothermic reaction?

Back

A reaction that releases energy, usually in the form of heat.

Front

What is an endothermic reaction?

Back

A reaction that absorbs energy from its surroundings.