Why are aqueous solutions of ionic compounds able to conduct electricity?

Show on a diagram the transfer of electrons between the atoms in the formation of MgO. Write symbols of cation and anion present in MgO.

Name the solvent in which ionic compounds are generally soluble.

A metal ‘X’ loses two electrons and a non-metal ‘Y’ gains one electron. Show the electron dot structure of compound formed between them. Is it ionic or covalent? Does it have high melting point or low? Will it conduct electricity in solid state or in aqueous solution and why? Will it be soluble in water?

State reasons for the following observations:

(a) The shining surface of some metals becomes dull when exposed to air for a long time.

(b) Zinc fails to evolve hydrogen gas on reacting with dilute nitric acid.

(c) metal sulphides occur mainly in rocks but metal halides occur mostly in sea and lake waters.