Question

A neutral atom of sodium (Na) has an atomic number of 11 and a mass number of 23. How many neutrons would be found in the nucleus of this atom of sodium?

34
23
12
11

Answer 1

11

Explanation:

The number of electrons is equal to the number of protons when the atom is neutral.

Answer 2

Mass number = atomic number + number of neutrons
23 = 11 + n
n = 23 - 11 = 12

Therefore, thre are 12 neutron in the neucleus of a Sodium atom.