Question

Give the number of protons and electrons in each of the following common ions: K1, Mg21, Fe31, Br2, Mn21, C42, Cu21.

Answer 1

No. of protons = Atomic No.

No. of electrons = Atomic No. - Magnitude of charge with sign

K⁺

No. of protons = 19

No. of electrons = 19 - 1 = 18

Mg²⁺

No. of protons = 12

No. of electrons = 12 - 2 = 10

Fe³⁺

No. of protons = 26

No. of electrons = 26 - 3 = 23

Br^-

No. of protons = 35

No. of electrons = 35 - (-1) = 36

Mn²⁺

No. of protons = 25

No. of electrons = 25 - 2 = 23

C^4-

No. of protons = 6

No. of electrons = 6 - (-4) = 2

Cu²⁺

No. of protons = 29

No. of electrons = 29 - 2 = 27