he following diagram shows the increasing value of (n+l). Ascending order of energies of various atomic orbitals is given below.

<1s <2s <2p <3s <3p <4s <3d <4p <5s
<4d <5p <6s <4f <5d <6p <7s <5f <6d <7p
<8s.....

The electronic configuration of some elements in the increasing atomic number (Z) value is given below

For carbon (C) atom (Z=6), where does the 6th electron go?
Whether the electron pairs up in the same p-orbital or will it go to the next p-orbital?

Hund’s Rule

According to this rule electron pairing in orbitals starts only when all
available empty orbitals of the same energy (degenerate orbitals) are singly
occupied.

The configuration of Carbon (C) atom (Z=6) is 1s²s²2p² .The first four electrons go into the 1s and 2s orbitals. The next two electrons go into separate 2p orbitals, with both electrons having the same spin.

Note that the unpaired electrons in the 2p orbitals are shown with parallel
spins.

page no:118
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