Atomic Number and Mass Number

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

How does the atomic number relate to the number of electrons in a neutral atom?

Back

In a neutral atom, the number of electrons is equal to the atomic number.

Front

What is the mass number of an atom?

Back

The mass number is the total number of protons and neutrons in the nucleus of an atom.

Front

How do you calculate the mass number of an atom?

Back

Mass number = Number of protons + Number of neutrons.

Front

What subatomic particles are found in the nucleus of an atom?

Back

Protons and neutrons are the subatomic particles found in the nucleus.

Front

What is the charge of a proton?

Back

A proton has a positive charge.

Front

What is the charge of a neutron?

Back

A neutron has no charge (it is neutral).

Front

What is the charge of an electron?

Back

An electron has a negative charge.

Front

Which subatomic particles contribute to the mass of an atom?

Back

Protons and neutrons contribute almost all the mass of an atom.

Front

Where is most of the mass of an atom located?

Back

Most of the mass of an atom is located in the nucleus.