Question

What is the electronic configuration of a selenium atom (se)?

Answer 1

1s22s22p63s23p63d104s24p4
or
[Ar] 3d10 4s2 4p4

Answer 2

Answer:

$1s^{2}2s^{2}2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{10} 4p^{4}$

Explanation:

For this exercise is necessary to know the atomic number of Se, which is 34 and indicate the numbers of electrons that has this atom.

For the electronic configuration you just need to follow the direction of the arrow indicated in the attached image, which shows the distribution of the electrons in the atomic orbitals, until complete the 34 electrons that has the selenium atom. The super index indicates the number of electrons in a specific atomic orbital. Then the electron configuration of selenium atom is:

$1s^{2}2s^{2}2p^{6} 3s^{2} 3p^{6} 4s^{2} 3d^{10} 4p^{4}$