Understanding Chemical Units

What are the basic building blocks of matter called?

• Atoms

• Molecules

• Elements

• Cells

What is a substance made of two or more elements called?

• Mixture

• Element

• Compound

• Solution

What do we call a change that produces new substances?

• Nuclear change

• Chemical change

• Biological change

• Physical change

Which law states that mass cannot be created or destroyed in a chemical reaction?

• Law of Conservation of Mass

• Law of Energy Conservation

• Law of Thermodynamics

• Law of Chemical Equilibrium

What is the smallest unit of an element that retains its properties?

• Element

• Molecule

• Compound

• Atom

What is the term for a chemical combination of two or more atoms?

• Atom

• Molecule

• Compound

• Element

What happens to the mass of reactants and products in a chemical reaction?

• The mass of reactants equals the mass of products.

• The mass of reactants can change during the reaction.

• The mass of products is always zero.

• The mass of reactants is greater than the mass of products.

What is the process called when substances react to form new substances?

• Physical change

• Chemical formula

• Element transformation

• Chemical reaction

Can you name a common compound made of hydrogen and oxygen?

• ammonia

• hydrogen peroxide

• methane

• water

What is the term for a substance that speeds up a chemical reaction without being consumed?

• catalyst

• reactant

• inhibitor

• solvent