Question

If a potassium atom has an atomic number of 19 and a mass number of 39, how many protons, electrons, and neutrons are in the atom?

Answer 1

Answer: The Atom would have:

9 protons

19 electrons (since atoms are electrically neutral and have the same number of electrons as protons)

20 neutrons

Explanation: Hope this Helps.

Answer 2

proton number = atomic number = 19
electron number = proton number | for a neutral atom = 19
neutrons = mass number-atomic number
= 39-19 = 20