a. `Mg(Z=12),(1s^(2),2s^(2),2p^(6),3s^(2))` Lewis symbol `rArr ddot(Mg)`
b. `Na(Z=11),(1s^(2),2s^(2),2p^(6),3s^(1))` Lewis symbol `rArr dot(Na)`
c. `B(Z=5),(1s^(2),2s^(2),2p^(1))` Lewis symbol `rArr underset(.)dot(B). `
d. `O(Z=8),(1s^(2),2s^(2),2p^(4))` Lewis symbol `rArr underset(..)ddot(O): `
e. `N(Z=7),(1s^(2),2s^(2),2p^(3))` Lewis symbol `rArr ddotNvdots`
f. `Br(Z=35),(1s^(2),2s^(2),2p^(6),3s^(2),3p^(6),3d^(10),4s^(2),4p^(5))` Lewis symbol `rArr underset(.)( :ddotBr: )`