Chemical Formulas and Reactions 2024 Fall Review 7th grade

Front

What is a chemical change?

Back

A change in which a substance (or substances) is changed into one or more new substances with different properties than the original substances.

Front

How does a physical change differ from a chemical change?

Back

Chemical changes produce a new substance, while physical changes do not change the substance itself.

Front

What is a sign of a chemical change?

Back

An unexpected color change.

Front

What does the formula 6CO₂ represent in terms of atoms?

Back

It contains 6 carbon atoms and 12 oxygen atoms.

Front

Define a compound.

Back

A substance composed of two or more elements chemically combined in a definite proportion.

Front

What is a physical change?

Back

A change that affects one or more physical properties of a substance without altering its chemical composition.

Front

Give an example of a physical change.

Back

Melting ice is an example of a physical change.

Front

What is a reactant?

Back

A substance that takes part in and undergoes change during a reaction.

Front

What is a product in a chemical reaction?

Back

A substance that is formed as a result of a chemical reaction.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, matter is neither created nor destroyed.