Reaction

The video tutorial explains the formation of new chemical bonds, differentiates chemical reactions from physical changes, and defines the terms reactants and products. Chemical reactions involve the formation of new substances, unlike physical changes where particles rearrange without changing themselves.

What is formed when new bonds are created in a chemical reaction?

• A new element

• A new mixture

• A new chemical substance

• A new physical state

How do chemical reactions differ from physical changes?

• Chemical reactions are reversible, while physical changes are not.

• Chemical reactions create new substances, while physical changes do not alter the substances themselves.

• Chemical reactions involve energy release, while physical changes do not.

• Chemical reactions occur only in liquids, while physical changes occur in all states of matter.

Which of the following best describes a physical change?

• New substances are formed.

• Energy is absorbed or released.

• The chemical composition changes.

• Particles rearrange but remain unchanged.

In a chemical reaction, what are the substances called that are used up?

• Elements

• Catalysts

• Reactants

• Products

What term is used for the substances that result from a chemical reaction?

• Products

• Compounds

• Reactants

• Catalysts