What is meant by the line?

Hydrogen can be easily oxidised an reduced and further acts as ligand to metals?

Dear students,

• Hydrogen reduces some metal ion in aqueous solution and oxide of metals into corresponding metals.

$H_2+P{d}^{2+}\to Pd+2H^{+}$

• Some dihydrogen complexes contains intact hydrogen as a ligand in which intermediate in metal catalysis reaction involves.

So above mentioned points can help you to understand your line that hydrogen can oxidize ,reduced and acts as a ligand in some coordinated complexes.

Regards