Question

total number of electrons in 4.2 gram of an 3 minus ion is

Answer 1

Nitrogen-Symbol-N -7(atomic number)
N³⁻ ion = 1s²2s²2p⁶
Total number of electrons =10
atomic mass of N=14
14g of N³⁻ ion contains 10NA electrons
where NA - Avagadro number
so, 1 g of N³⁻ ion =10NA/14
∴4.2g of N³⁻ ion =4.2x 10NA/14
=3NA

∴The total number of electrons in 4.2g of N3- ion 3NA ---- option (3)is correct
I hope u like the answer