How many protons, neutrons, and electrons are in a neutral atom of sodium?

1 Answer
May 23, 2016

Protons 11
Neutrons 12
Electrons 11

Explanation:

The subatomic particles (protons, neutrons and electrons) can be determined using some basic information from the periodic table.

The Atomic Number of an element is always equal to the number of protons. The Mass Number of an element is equal to the protons added to the neutrons.

The element Sodium has an atomic number of 11 and an average atomic mass of 22.98 which makes the mass number 23.

Therefore

An atomic number of 11 means this atom will have 11 protons.

A mass number of 23 means 23 - 11 this atom will have 12 neutrons.

Since this atom is neutral the positive protons must be equal to the negative electrons. This atom will have 11 electrons.

Protons 11
Neutrons 12
Electrons 11