Match the items in column I with items in column II and select the correct option.

Matrix:

	Column I		Column II
a)	CO32-	i)	1u
b)	O2	ii)	Ion
c)	HCl	iii)	Polyatomic ion
d)	Charged species	iv)	Phosphorus molecule
e)	1/12th mass of one C atom	v)	Molecule of compound
f)	Tetra-atomic	vi)	Molecule of an element

Polyatomic ions are formed from groups of joined atoms. $C{O}_3^{2-}$ is a polyatomic ion. $O_2$ is a molecule of an element.

HCl is a molecule of a compound which is formed when two or more atoms of different elements combine together chemically.

When an atom gets a charge, it is called an ion. Ions are charged species. One atomic mass unit that is 1u is equal to 1/12^th mass of one C atom.

$P_4$  is a tetra- atomic molecule where four atoms of an element are chemically bonded to form its molecule.