Physical Periodicity

Question 1

Atomic Radius down a group

Answer 1

NC↑
↑ inner shell electrons
↑ shielding effect
NC>SE
NA=NC-SE
NA↓
Atomic Radius ↑

Question 2

Atomic Radius across a period

Answer 2

NC↑
≈inner shell electrons
≈shielding effect
NC>SE
NA=NC-SE
NA↑
Atomic Radius↓

Question 3

Cations have smaller radius than its corresponding atom

Answer 3

NC≈
NA for valence ↑ as same no. of protons attract fewer electrons
∴ cations have smaller ionic radius

Question 4

Anions have bigger radius than its corresponding atom

Answer 4

NC≈
NA for valence ↓ as same no. of protons attract more electrons
∴ anions have bigger ionic radius

Question 5

Ionic radius decreases across iso electronic series ( Na+ vs Mg2+)

Answer 5

NC↑, no. of electron same
NA for valence↑ as more protons attract same electrons
∴ ionic radius ↓

Question 6

Anions radius bigger than cations in same period
(P3- vs Na+)

Answer 6

Anions higher NC and one additional filled electronic shell than cations

NA for valence ↓ as electrons are further away from nucleus and have ↑ SE

SE>NC

∴ anions have bigger ionic radius

Question 7

ionic radius graph

Answer 7

Question 8

ionisation energy
small dip between 12 &13

Answer 8

higher energy 3p vs 3s subshell, ↓NA, less energy required to remove

Question 9

ionisation energy
small dip between 15 &16

Answer 9

doubly filled 3p vs singly filled 3p, inter electronic repulsion with paired electron,↓NA, less energy required to remove

Question 10

atomic radius graph

Answer 10

↑NC
≈ SE
↑ NA, thus smaller radius

Question 11

drop in ionisation energy between grp 18 and grp 1 of next period

Answer 11

loosely held electron is further away, ↑ SE
SE>NC
NA↓
Less energy required to remove