The atomic number of two atoms ‘X’ and ‘Y’ are 14 and 8 respectively.

State:

(a) the period to which ‘X’ belongs.

(b) the formula of the compound formed between ‘X’ and ‘Y’.
(Do not identify X and Y)

(a) The atomic number of X is 14
Electronic configuration ⟶ 2, 8, 4

Number of electron shells = 3, hence X belongs to period 3

(b) The atomic number of Y is 8
Electronic configuration ⟶ 2, 6

X has a valency of 4 and Y has valency of 2

$\overset{\phantom{4}{4}}{\text{X}} \space {\swarrow}\mathllap{\searrow} \space \overset{2}{\text{Y}} \Rightarrow \underset{\phantom{2}{2}}{\text{X}} \space {\swarrow}\mathllap{\searrow} \underset{\phantom{4}{4}}{\text{Y}} \\[1em] \text{X}$2\text{Y}4

∴ Simplified formula of the compound is XY₂