Question

The electronic configuration of two elements $X$ and $Y$ is given below :
$X=1s^2$, $2s^{2}2p^6$, $3s^{2}3p^6$, $4s^2$
$Y=1s^2$, $2s^{2}2p^6$, $3s^{2}3p^5$
The formula of the ionic compound that can be formed between these elements is

• A. $XY$
• B. $X{Y}_2$
• C. $X_{2}Y$
• D. $X{Y}_3$

Answer 1

Answer: (B)

$X$ belongs to alkaline earth metal group $(=Ca)$, ${\rm Y}$ belongs to halogen group $(=Cl)$. So, the possible ionic compound that can be formed is $CaC{l}_2$