Any electron is not fixed to any sub-shell or orbital.
If you provide sufficient energy to an electron, it would make transition to any of the higher energy orbitals and then come back to the lower orbitals radiating energy.
Any electron is not fixed to any sub-shell. Electrons gain energy and make transition to
higher energy levels. Then they loose energy and come back to lower levels radiating energy. Hence, for any electron to come from 3s sub-shell to 2s sub-shell, energy must be
given out.
An electron in a 2s orbital is on average closer to the nucleus.
1s^2 2s^2 2p^6 3s^2 3p^2
Sodium.
Sodium has 3 energy levels, 1s, 2s, 2p, and 3s.
it is 1s(2) 2s(2) 2p(6) 3s(2) 3p(4)
An electron in a 2s orbital is on average closer to the nucleus.
2s.3s
The number preceding the name of a sublevel ("s") indicates in which electron shell it belongs. Thusly, 2s is the second shell and 3s is the third.
1s^2 2s^2 2p^6 3s^2 3p^2
Sodium.
Sodium has 3 energy levels, 1s, 2s, 2p, and 3s.
1s 2s 2p 3s 3p 4s 3d 2p
1s^2 2s^2 2p^6 3s^2 3p^2
it is 1s(2) 2s(2) 2p(6) 3s(2) 3p(4)
1s^2 2s^2 2p^6 3s^2 3p^5
1s 2 2s 2 2p 6 3s 2 3p 6 4s 1
The 2s orbital and 3s orbital both have the same spherical shape and can hold a maximum of two electrons of opposite spin. They only differ because the 3s orbital is further out from the nucleus than the 2s orbital, thus the 3s orbital has a higher energy value.