Question

which element has higher sheilding effect ? (a) Li (b) Na (c) K​

Answer 1

Answer:  

Element lithium has higher shielding effect.

Explanation:

shielding effect or screening effect means electron repulsion

As we move down the group atomic number increases due  increase in number of shells ,hence shells and orbital also increases.

Shielding effect depends on  sub shells involved in it

ex.

electronic configuration

• Li =   1 s^2   2 s^1

        here shells involved in screening effect is 1 s^1

• Na = 1 s^2  2 s^2 2 p^6 3 s^1

        here shells involved in screening effect is 2 p^6

from here we came to know that sub shell involved in shielding effect is one which is beyond last shell

Magnitude of sub shell

1 s > 2 p >3 d > 4 d > 5 d > > 4 f

As atomic  number increases sub shells increase in order s, p, d, f

As we saw above magnitude of screening effect and sub shells involving in screening effect shows how higher is screening effect

Li atom involves 1 s orbital which has highest magnitude

Remember a shortcut

shielding effect or screening effect is inversely proportional to atomic radius

shielding effect or screening effect ∝ 1 / atomic radius

                                                             

Answer 2

Answer:

answer Is c please mark as brainlist