Question

A dipositive ion has an electronic arrangement $2,8,8$. Find out the number of electrons, protons and neutrons in that element if its mass number is $40$.

Answer 1

Electronic configuration of dipositive ion is $2,8,8$ hence its neutral atom will have configuration as $2,8,8,2$, which shows total number of electrons/protnes = $20.$

Mass = proton + nutron i.e. $40=20+20$

The number of electrons, protons and neutrons in that element = $20,20,20.$