Construct the electronic formulas of the ions K, Ca, Na, Mg, S, Cl.

Electronic formula – a record of the distribution of electrons available in an atom by energy levels and orbitals.
All the proposed chemical elements are in the main subgroups, therefore, in order to determine the number of electrons at the last energy levels, it is enough to look into the periodic system. Since the group number for the elements of the main subgroups shows the number of electrons at the last energy level.
+ 19K) 2) 8) 8) 1 electronic formula: 1s2 2s2 2p6 3s2 3p6 4s1
+ 20Ca) 2) 8) 8) 2 electronic formula: 1s2 2s2 2p6 3s2 3p6 4s2
+ 11Na) 2) 8) 1 electronic formula: 1s2 2s2 2p6 3s1
+ 12Mg) 2) 8) 2 electronic formula: 1s2 2s2 2p6 3s2
+ 16S) 2) 8) 6 electronic formula: 1s2 2s2 2p6 3s2 3p4
+ 17Cl) 2) 8) 7 electronic formula: 1s2 2s2 2p6 3s2 3p5