NH3 is normally encountered as a gas with a pungent odor. It is formed from hydrogen and nitrogen (equation given below). A chemist pours a mixture of nitrogen gas and hydrogen gas in a 1.0 litre reaction vessel in 1:3 ratio. The equilibrium constant for the reaction is 1.0 × 10–4, and the equilibrium value of [H(g)] is 0.12 mol/L. Calculate the equilibrium value of [NH3] N2(g) + 3 H2(g) ⇔ 2 NH3(g)

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.

they are all solids.