Write the name of $Cr_2O_3$ according to stock notation.

Predict the formula of the stable binary compounds that would be formed by the combination of the following pairs of elements:
$(a)$ Lithium and oxygen
$(b)$ Magnesium and nitrogen
$(c)$ Aluminium and iodine
$(d)$ Silicon and oxygen
$(e)$ Phosphorus and fluorine
$(f)$ Element $71$ and fluorine

Which of the oxidation state$(s)$ is/are shown by the element sulphur?

The formula of the oxide of an element $M$ having $IE_1 = 100 \ kJ/mol$,$IE_2 = 250 \ kJ/mol$ and $IE_3 = 1500 \ kJ/mol$ should be:

The valency of sulphur in sulphuric acid is

Among the following,the number of elements showing only one non-zero oxidation state is $O, Cl, F, N, P, Sn, Tl, Na, Ti$.