An element $X$ belongs to the $3rd$ period and group $16$ of the Modern Periodic Table.
$(a)$ Determine the number of valence electrons and the valency of $X$.
$(b)$ Write the molecular formula of the compound formed when $X$ reacts with hydrogen and draw its electron dot structure.
$(c)$ Name the element $X$ and state whether it is metallic or non-metallic.

(N/A) The electronic configuration of $X$ is $2, 8, 6$.
Number of valence electrons $= 6$.
Valency $= 8 - 6 = 2$.
$(b)$ When $X$ reacts with hydrogen,it forms a compound with the molecular formula $H_2X$. Since $X$ is Sulphur,the formula is $H_2S$. The electron dot structure is shown in the image provided.
$(c)$ The element $X$ is Sulphur $(S)$. It is a non-metal.