Two elements A and B have the electronic configuration as:
A = 1s²2s²2p⁶3s² and B = 1s²2s²2p⁵
Write the empirical formula of the substance containing A and B.

What type of bonding would you expect between:
(i) a metal and a non-metal
(ii) a non-metal and another non-metal?

Give reasons in one or two sentences for the observation that in their compounds non-metals form anions and not cations.

Out of Na and K, which will form a more stable ionic bond?

Which will have a greater lattice enthalpy: NaCl or MgO?

Is  a covalent molecule always formed between two similar atoms?

Why sodium chloride is a solid whereas carbon tetrachloride is a liquid?

Why NaCl gives a white percipitate with AgNO₃ solution but CCl₄ does not?

20.

What is covalency of an element?