Write down the following electronic formulas: Ca, P, S, N

To write an electronic formula, you need to know that:
– the serial number is equal to the nuclear charge and the number of electrons;
– the number of the period is equal to the number of energy levels;
– the group number shows the number of electrons in the last $ level
– the level has sublevels – s, p, etc.
1) Ca (No. 20, period 4, group 2). Ca +20 1s2 2s22p6 3s23p6 4s2.
2) P (No. 15, period 3, group 5). P + 15 1s2 2s22p6 3s23p3.
3) S (No. 16, period 3, group 6). S + 16 1s2 2s22p6 3s23p4.
4) N (No. 7, period 2, group 5). N + 7 1s2 2s22p3