Question

atoms or ions in order atoms or ions of decreasing size D.0.O CI, Cl , Ar O. 0. 0 Br,Cl, I 0. 0. 0 Ne, Li, Be

Answer 1

1)

Cl and Ar in same period.

Size decreases as we move from left to right in a period.

So, Cl > Ar

Cl- > Cl because Cl- has one extra electron and hence more electron-electron repulsion to increase the size

Answer: Cl-, Cl, Ar

2)

Br, Cl and I are in same group

Rule: Atomic size increases as we move down a group. This is because one extra shell is added as period number increases.

So, order of size is: I > Br > Cl

Answer: I, Br, Cl

3)

Ne, Li and Be are in same period.

Rule: Atomic size decreases as we move from left to right in a period. This is because one extra proton is added.

So, order of size is: Li > Be > Ne

Answer: Li, Be, Ne