Write Lewis symbols for the following atoms and ions:
`S` and `S^(2-), Al` and `Al^(3+),H` and `H^(ө)`

Explanation

(i) S and `S^(2-)`
The number of valence electrons in sulphur is 6.
The Lewis dot symbol of sulphur (S) is `:overset(..)S:`
The dinegative charge infers that there will be two electrons more in addtion to the six valence electrons. Hence, the Lewis dot symbol of `S^(2-)` is `[:overset(..)underset(..)S:]^(2-)`.
(ii) Al and `Al^(3+)`.
The number of valence electrons in aluminium is 3.
The Lewis dot symbol of aluminium (Al) is `* underset(.)Al*`.
The tripositive charge on a species infers that it has donated its three electrons. Hence, the Lewis dot symbol is `[Al]^(3+)`.
(iii) H and `H^(-)`
The number of valence electrons in hydrogen is 1.
The Lewis dot symbol of hydrogen (H) is `H*`
The uninegative charge infers that there will be one electron more in addition to the one valence electron. Hence, the Lewis dot symbol is `[overset(..)H]^(-)`.