Chemical Formulas and Reactions 2024 Fall Review 7th grade

Front

What is a compound?

Back

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

Front

How does a physical change differ from a chemical change?

Back

A chemical change produces a new substance, while a physical change does not change the substance itself.

Front

What indicates a chemical reaction when combining hydrochloric acid with baking soda?

Back

The formation of bubbles indicates a chemical reaction.

Front

What is the chemical symbol for Zinc?

Back

Zn

Front

Which of the following is a compound: Co, O2, C, CO2?

Back

CO2 is a compound.

Front

What is the definition of a chemical reaction?

Back

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction.

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means.

Front

What is the difference between an atom and a molecule?

Back

An atom is the smallest unit of an element, while a molecule is a group of two or more atoms bonded together.

Front

What is a reactant in a chemical reaction?

Back

A reactant is a substance that undergoes change during a chemical reaction.