Understanding Chemical and Physical Changes

What is a key characteristic of a physical change?

• The arrangement of atoms remains the same.

• The identity of the substance changes.

• New substances are formed.

• Atoms are rearranged to form new molecules.

What happens at the atomic level during a chemical reaction?

• Atoms remain in their original arrangement.

• Atoms are destroyed.

• Atoms are created.

• Atoms rearrange to form new substances.

In a chemical reaction, what are the substances called that are present before the reaction?

• Products

• Inhibitors

• Reactants

• Catalysts

Why does the mass remain constant in a chemical reaction?

• New atoms are created.

• Atoms are rearranged, not created or destroyed.

• Atoms change their mass.

• Atoms are destroyed.

What analogy is used to explain the conservation of mass in a chemical reaction?

• Playing with LEGO bricks

• Building a house

• Cooking a meal

• Writing a book