An atom of strontium -90 contains

Question

(A) 38 electrons, 38 protons, 52 neutrons

(B) 38 electrons, 38 protons, 90 neutrons

(C) 52 electrons, 52 protons, 38 neutrons

(D) 52 electrons, 38 protons, 38 neutrons

Answer 1

A because strontium is atomic no. 38 meaning it MUST have 38 protons and 38 electrons. The difference between protons and mass is neutrons.