Understanding Chemical Reactions

What is a chemical reaction?

• A process where substances freeze.

• A process where substances change color.

• A process where substances melt.

• A process where new substances are formed.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What does the Law of Conservation of Matter state?

• Atoms disappear in a chemical reaction.

• Matter cannot be created or destroyed.

• The total number of atoms changes in a chemical reaction.

• Matter can be created or destroyed.

Tags

NGSS.MS-PS1-5

Which of the following is NOT a property of matter?

• Magnetism

• Flammability

• Color change

• Density

What happens during a physical change?

• Atoms are destroyed.

• Matter is created.

• The state of matter changes.

• New substances are formed.

Tags

NGSS.MS-PS1-4

Which of the following is an example of a chemical change?

• Boiling water

• Freezing water

• Burning steel wool

• Melting ice

Tags

NGSS.MS-PS1-2

What role does a catalyst play in a chemical reaction?

• It speeds up the reaction.

• It slows down the reaction.

• It stops the reaction.

• It becomes part of the new substance.

Tags

NGSS.HS-PS1-5

What is formed when reactants combine or rearrange?

• Products

• Molecules

• Reactants

• Atoms

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is NOT a result of a chemical reaction?

• New substances are formed.

• Atoms rearrange.

• The total mass changes.

• The properties of substances change.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What is an example of a phase change?

• Rusting iron

• Burning wood

• Melting ice

• Combustion of propane

Tags

NGSS.MS-PS1-4

What is the smallest particle of matter?

• Molecule

• Element

• Atom

• Compound