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

An element ‘X’ belongs to 3^rd period and group 16 of the Modern Periodic Table.
a. Determine the number of valence electrons and the valency of ‘X’.

b. Molecular formula of the compound when ‘X’ reacts with hydrogen and write its electron dot structure.

c. Name the element ‘X’ and state whether it is metallic or non-metallic.

(a) Since element X belongs to 3^rd period and group 16 that means it has 3 shells and 6 valence electrons. So its valency is 2 because it requires 2 electrons to acquire stable noble gas configuration.

(b) Since hydrogen has 1 valency and element X has 2 valency. So the molecular formula will be H₂X.

(c) Since element X belongs to 3rd period and group 16 that means it has 3 shells and 6 valence electrons so its electronic configuration will be 2, 8, 6. Hence element X is sulphur (S) and it is non-metallic.