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?
Charge = +3
Mass number = 27
Number of neutrons = 14
Number of protons = atomic number
Atomic number = mass number – number of neutrons = 27 - 14 = 13
This is the atomic number of aluminium. Therefore, this element is aluminium (Al).
Number of electrons in the Al atom = 13
Number of electrons in the AI3+ ion = 13 – 3 = 10
The correct option is B.