Explain the polarity of covalent bonds in `H_(2)O and HCl.`

Define: covalent bond

Define : Non -polar covalent bond

Define : Polar covalent

Which one is covalent bond ?

On the basis of lanthanoid contraction, explain the following : Nature of bonding in La_(2)O_(3) and Lu_(2)O_(3) .

Explain why in the laboratory preparation of H_(2)O_(2) : HCL or HN O_(3) is not used,

Explain why covalent bonds possess directional property.

Explain the formation of H_(2) molecule on the basis of valance bond theory.

Show that F forms ionic bond with Na but it forms covalent bond with H. (The atomic numbers of H, F and Na are .1, 9,and 11,respectively)