Atoms & Chemical Reactions Unit 2 Test (updated 2024)

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What charge do neutrons have?

Back

Neutrons have no charge (they are neutral).

Front

What is the difference between ionic and covalent bonds?

Back

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Front

What happens during a chemical change?

Back

A new substance is formed during a chemical change, while no new substance is formed during a physical change.

Front

Why do protons and electrons stay near each other?

Back

Protons (positive charge) and electrons (negative charge) attract each other due to their opposite charges.

Front

What is an atom?

Back

An atom is the smallest unit of matter that retains the properties of an element.

Front

What are the three main subatomic particles?

Back

The three main subatomic particles are protons (positive charge), neutrons (no charge), and electrons (negative charge).

Front

What is 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.