An element ' X ' belong to 3‌rd ‌ period and group 13 of the Modern Periodic Table.
(a) Determine the valence electrons and the valency of ' X '.
(b) Molecular formula of the compound formed when ' X ' reacts with an element ' Y ' (atomic number =8 ).
(c) Write the name and formula of the compound formed when ' X ' combines with chlorine.