Question

If the atomic number of Lithium is 3 and its mass number is 7, how many protons, electrons, and neutrons does a neutral

atom of Li have

Answer 1

Protons = 3

Neutrons = 4

Electrons = 3

Explanation:

For every atom, the atomic number is equal to the number of protons.

In a neutral atom (atom with no charge) the number of protons is equal to the number of electrons.

To calculate neutrons subtract the number of protons (atomic number) from the rounded molar mass:

7 - 3 = 4 neutrons