Electron configuration tolc med 2015

this is a question I found on tolc med but the solution seemed weird to me.
is this type of information included? first time seeing this method


this is just another way of writing the electronic configuration, looking only at the atom’s shells
the atom shells are K² L⁸ M¹⁸ N³² so K holds 2e⁻ and so on
in the notation we have gone over in class, it goes into even more detail, looking at the atom’s shells and subshells
K² = 1s²
L⁸ = 2s² 2p⁶
M¹⁸ = 3s² 3p⁶ 3d¹⁰
N³² = 4s² 4p⁶ 4d¹⁰ 4f¹⁴

So being told the element has an electronic configuration of 2, 8, 18, 7 is the same as saying it has 2+8+18+7 e⁻
So a structure of 1S² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁵ which is the element bromine