Chemical Reactions

What are reactants in a chemical reaction?

• Substances that undergo change during a chemical reaction.

• Products formed after the reaction is complete.

• Catalysts that speed up the reaction process.

• Inert substances that do not participate in the reaction.

What are products in a chemical reaction?

• Substances that are formed as a result of a chemical reaction.

• Substances that are consumed during a chemical reaction.

• Elements that remain unchanged in a chemical reaction.

• Catalysts that speed up a chemical reaction.

What is the law of conservation of mass?

• Matter can be created but not destroyed in a chemical reaction.

• Matter cannot be created or destroyed in a chemical reaction.

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

• Mass can change forms but is always conserved in a chemical reaction.

What is a compound?

• A substance formed when two or more different elements chemically bond together.

• A mixture of two or more substances that retain their individual properties.

• A single element that cannot be broken down into simpler substances.

• A solution where one substance is dissolved in another.

What is a chemical equation?

• A numerical representation of a chemical reaction.

• A symbolic representation of a chemical reaction showing the reactants and products.

• A graphical representation of chemical compounds.

• A verbal description of a chemical process.

______ is (are) made of more than one atom.

• A molecule

• An atom

• A compound

• An electron

What kind of scientist forms new chemicals by studying chemical reactions?

• Materials scientist

• Biochemist

• Environmental scientist

• Nuclear physicist

Is TNT exploding a physical or a chemical change?

• Physical change

• Chemical change

• Both physical and chemical change

• Neither physical nor chemical change

What is an element?

• A pure substance that cannot be broken down into simpler substances.

• A mixture of two or more substances.

• A compound formed by chemical reactions.

• A type of molecule that contains only one kind of atom.

If you start a chemical reaction with 5 atoms of helium, how many atoms will you have after?

• 3 atoms

• 5 atoms

• 7 atoms

• 10 atoms