Chemical Reactions Quiz

What is a chemical reaction?

• A change in shape

• Atoms rearranging to form new substances

• A substance freezing

• Atoms disappearing

Which of the following is always true during a chemical reaction?

• New atoms are created

• The number of atoms increases

• Atoms are rearranged

• Only one product is formed

What are the starting substances in a chemical reaction called?

• Molecules

• Products

• Reactants

• Mixtures

What are the substances formed after a chemical reaction called?

• Atoms

• Reactants

• Bonds

• Products

Which of the following is a chemical reaction?

• Boiling water

• Melting chocolate

• Burning wood

• Breaking a pencil

Which type of change makes a new substance?

• Physical

• Reversible

• Chemical

• Mechanical

What does the law of conservation of mass say?

• Mass increases in every reaction

• Mass is always lost

• Mass stays the same

• Mass doubles

In a chemical reaction, atoms are:

• Destroyed

• Created

• Rearranged

• Evaporated

Which of these is a product of burning magnesium?

• Magnesium oxide

• Oxygen

• Magnesium

• Heat and light

What holds atoms together in molecules?

• Air pressure

• Chemical bonds

• Magnetic force

• Water