What is the electron configuration of Oxygen? Give it in terms of shells and subshells.

[He] 2s2 2p4There are 4 potential shells of electrons for the elements in the periodic table, denoted by the first number, 1 to 4.Within each shell there is a matching number of subshells; in shell 1 there is 1 subshell, in shell 2 there are 2 subshells, in shell 3 there are 3 subshells, and in shell 4 there are 4 subshells. The names of these subshells are as follows: the 1st subshell (found in all 4 shells) is the s subshell, the 2nd subshell is the p subshell. For this question, these are the only ones necessary but there are two more. The s subshell holds 2 electrons and the p subshell holds 6 electrons. When writing out how many electrons are in each shell and subshell we follow this order:1) Write the number of the Shell e.g. 12) Write the letter of the subshell e.g. s3) Write the number of electrons in the subshell e.g. 2= 1s2 This is the electron configuration of Helium in terms of shells (1) and subshells (s).Returning to the correct answer to the full question, oxygen has 8 total electrons. This means that the total number of electrons in its shells and subshells must add up to 8. So we know it must have a full 1st shell and subshell, so we can write 1s2, it must have a full s subshell in its 2nd shell, so we can write 2s2, and it must have 4 more electrons in its p subshell in its 2nd shell, so we can write 2p4. Writing this all together - 1s2 2s2 2p4The [He] denotes a shorthand version of simply writing out 1s2 to start, so 1s2 2s2 2p4 would also be acceptable but writing [He] shows more understanding and makes it easier for the examiner to see that you understand. This might also be the only acceptable form of writing electron configurations for some examination boards.