1.

(a) Write the electronic configuration of the element with atomic number 102. (b) What is lanthanoid contraction ? What is its effect on the chemistry of the elements which follow the lanthanoids?

Answer»

Solution :(a) NOBELIUM (Nb) has atomic number (102). It has the electronic configuration :
`1s^(2) 2S^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(10) 4s^(2) 4p^(6) 4d^(10) 4f^(14) 5s^(2) 5p^(6) 5d^(10) 5f^(14) 6s^(2) 6p^(6) 7s^(2)`
(b) The decrease in atomic and ionic size with increase in atomic number among lanthanoids is called lanthanoid contraction.
The elements after lanthanoids CLOSELY resemble with the elements exactly above them due to similar ionic size, e.g., ZR and HF.


Discussion

No Comment Found