Atomic Number and Mass Number

Front

What is the atomic number?

Back

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

Front

What is the mass number?

Back

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

Front

How do you calculate the mass number?

Back

Mass number = Number of protons + Number of neutrons.

Front

What subatomic particle has a positive charge?

Back

Proton.

Front

What subatomic particle has no charge?

Back

Neutron.

Front

What subatomic particle has a negative charge?

Back

Electron.

Front

If an atom has an atomic number of 6, how many electrons does it have?

Back

6 electrons (in a neutral atom, the number of electrons equals the atomic number).

Front

What is the atomic number of oxygen?

Back

8 (oxygen has 8 protons).

Front

What is the mass number of a carbon atom with 6 protons and 6 neutrons?

Back

12 (6 protons + 6 neutrons = 12).

Front

How many neutrons are in a sodium atom with a mass number of 23 and an atomic number of 11?

Back

12 neutrons (23 - 11 = 12).