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 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

Explanation

The element X has 3 electron shells and 6 valence electrons. Hence, its electronic configuration is (2, 8, 6) and its atomic number = 2+8+6 = 16.
  a) Number of valence electrons is 6 and valency is 2.
b] Since valency of hydrogen is I, when X reacts with hydrogen, formula of compound formed is XH, Electrondot structure: c) X has the atomic number 16 and is sulphur. It is non metallic