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  What is the electronic configuration of sodium and argon 1.1                        

         How many electrons are present in the M shell of argon which is the outermost shell?


         How many more electrons can be accommodated in the M shell?

         10 more electrons

What will be the number of subshells in the shells M and N?

 M = 3

 N = 4

 See the subshells present in each shell 1.2


Which subshell is common to all shell?


Fill in the table 1.3

Table 1.4      

Write the subshells in the increasing order of their energy


What is the atomic number of the lithium?


Complete the table 1.5, writing the subshell electronic configuration of the given elements

Write the subshell electronic configuration of potassium (19K)

1s2  2s2  2p6  3s2  3p6  4s1

What about its shell wise electronic configuration?


See the graph in Tb (fig 1.2)

Compare the energies of 1s and 2s subshells. Which has lower energy?

1s has lower energy

Of the 3s and 3p subshells, which has higher energy? What about the 3d and 4s?

3p has higher energy than 3s, 3d has higher energy than 4s.

The electronic configuration of scandium (21Sc) is 2,8,9,2. How can we write its subshell electronic configuration?

1s2  2s2  2p6  3s2  3p6  4s2  3d1

Write the electronic configuration of 22Ti and 23V.

22Ti – 1s2  2s2  2p6  3s2  3p6  4s2  3d2

23V – 1s2  2s2  2p6  3s2  3p6  4s2  3d3

Complete the table 1.6

Write the subshell electronic configuration of 24Cr.

1s2  2s2  2p6  3s2  3p6  3d4  4s2

Stable electronic configuration of Cr – 1s2  2s2  2p6  3s2  3p6  3d5  4s1

Correct electronic configuration of 29Cu is

1s2  2s2  2p6  3s2  3p6  3d10  4s1      

If the subshell wise electronic configuration of an atom is 1s2  2s2  2p6  3s2 , find answers to the following :

How many shells are present in this atom?


Which are the subshells of each shell?