Question

Write the correct increasing order for the following group 13 elements.

a)atomic radius b)ionisation enthalphy ​

Answer 1

Answer:

a) The increasing order of atomic radii of group 13 elements is :

Ga(135pm)<Al(143pm)<In(167pm)<Tl(170pm)

On moving down the group, the atomic radii increases. However due to poor shielding of nuclear charge by 3d electrons,

(135pm)

r

Ga

<

(143pm)

r

Al

Ga has 10 d electrons which do not screen the nuclear charge in an effective manner.

The electrons in the outermost shell of Ga experience more force of attraction towards nucleus than Al which decreases atomic radius.

Answer 2

Answer:

a) Atomic  Radius

Explanation: