Question

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

• A. 13
• B. 10
• C. 14
• D. 16

Answer 1

The correct option is B 10

From mass number and number of neutrons, we can calculate number of protons or electrons which is 13 (mass number - number of neutrons). Hence, the electronic configuration of this element would be 2, 8, 3. In order to become stable it would lose the last 3 electrons and gain 3 positive charges as given in the question. So, the resultant ion is left with 10 electrons. The element here is Al (aluminium).

Hence correct option is (B).