What are the number of sub-levels and electrons for the first four principal quantum numbers?

1 Answer
Oct 23, 2015

Answer:

For quantum number 1, the number of sub level is 1, number of electrons= 2.
For quantum number 2, no. of sub levels are 2, no. of electrons= 8. For quantum no. 3, sub levels are 3 and no. of electrons are 18.
For 4th quantum no. sub levels are 4 and electrons are 32.

Explanation:

You can easily calculate it with this method :

  1. Suppose the principal quantum number is symbolized as #n# the Azimuthal or secondary quantum number is symbolized as #l#
    the magnetic Q.N is #m#
    and the spin Q.N is #s#.

  2. #n# = which energy shell it is; #l# = number of sub-shells; #m# = number of orbitals as well as electrons.
    #l# =0, #n-1# and #m# = #+-# l = #-l, 0, +l#.

  3. For example, in case of principal quantum number 2,
    the result of #l# is = #n-1# = 2-1 = 1, which means the number of subshells are two : 0 and 1.

Now the result for #m# is : 0 = #s# (one orbital of subshell #s#) = 2 electrons. And for 1 = -1, 0, +1 = #P_x, P_y and P_z# (3 orbitals of subshell #p#), electron = 6 ( each orbital can contain maximum 2 electrons ) .

So the total number of electrons for principal quantum number 2 is 8 .