Question

An atom has an atomic number of 19 and a mass number of 39. How many electrons, protons and neutrons does it have

Answer 1

If an atom has an atomic number 19 and mass number 39 then:

Electrons = 19
Protons = 19
Neutrons = 20

Answer 2

Electrons =19
Protons =19
Neutrons=39-19=20