Question

The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?

Answer 1

Number of valence electrons= +3
This shows that atom had lost 3 electrons to become stable and reach the state of octet.

number of neutrons= 14
Mass number= 27
Number of electrons= 27-14
=13

so the number of electrons in the ion= 13-3
=10

hope it helps...

Answer 2

Mass no of the atom =27
No of protons =Mass No -No of neutron
==> 27-14
= 13
Since the element forms a positive trivalent cation
Therefore the no of electrons would be

No of protons - Magnitude of charge
13-3
===>10