Question

How many atoms can an element contain ?

Answer 1

Some elements are monoatomic i.e. they exist as single atoms e.g. He, Ne, Ar
Some elements are diatomic i.e. they exist as molecules of two atoms e.g. H2, N2, O2
Some elements are triatomic i.e. they exist as molecules of three atoms e.g. O3
Some elements are tetratomic i.e. they exist as molecules of four atoms e.g. P4

As far as I know fullerite C60 is the biggest molecule of an atom....