Question

6'). The ratio of a number of valence shell electrons to the number of penultimate shell electrons in Y2 atomic number is 34​

Answer 1

The electronic configuration for Y^2− is:

⇒Y^2− =1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6

Here, valence shell electrons= 8

Penultimate shell= 3

∴ Penultimate shell electrons= 18

∴ Ratio= 8:18=4:9

:)