Calculate the number of protons , electrons and neutrons in the following.
(a) Chloride ion `(Cl^(-))` with `Z = 17,A =35`
(b) Aluminium ions`(Al^(3+)) ` with `Z = 13 , A=27`

Explanation

(a) ` Cl^(-)` with Z= 17 ,A =35
Number of protons = 17
Number of electrons = 17 +1 ( as one negative charge which means gain of electron )
`=18`
Number of neutrons `= A-Z=35 -17 =18`
(b) `Al^(3+)` with Z=13
A=27
Number of protons = 13
Number of electrons `=13-3` ( As it has positive charges obtained by the loss of three electrons )
=10
Number of neutrons =` A-Z`
`=27-13`
`=14`