Question

Use Lewis symbols to show electron transfer between the following atoms to form cations and anions:

1. K and S
2. Ca and O
3. Al and N.

Answer 1

(a) $K$ and $S$:
The electronic configurations of $K$ and $S$ are as follows:
$K$ : $2, 8, 8, 1$
$S$ : $2, 8, 6$

Sulphur $(S)$ requires $2$ more electrons to complete its octet. Potassium $(K)$ requires one electron more than the nearest noble gas i.e., $Argon$. Hence, the electron transfer can be shown as:

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(b) $Ca$ and $O$:
The electronic configurations of $Ca$ and $O$ are as follows:
$Ca$ : $2, 8, 8, 2$
$O$ : $2, 6$
Oxygen requires two electrons more to complete its octet, whereas calcium has two electrons more than the nearest noble gas i.e., $Argon$. Hence, the electron transfer takes place as:

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(c) $Al$ and $N$: The electronic configurations of $Al$ and $N$ are as follows:
$Al$: $2, 8, 3$
$N$ : $2, 5$
Nitrogen is three electrons short of the nearest noble gas (Neon), whereas aluminium has three electrons more than Neon.
Hence, the electron transference can be shown as: