The first ionization enthalpy of Na, Mg and Si, respectively, are : 496, 737 and $$786 \mathrm{~kJ} \mathrm{~mol}^{-1}$$. The first ionization enthalpy ($$\mathrm{kJ} \,\mathrm{mol}^{-1}$$) of $$\mathrm{Al}$$ is :

In metallurgy the term "gangue" is used for :

The reaction of zinc with excess of aqueous alkali, evolves hydrogen gas and gives :

Lithium nitrate and sodium nitrate, when heated separately, respectively, give :