Fill in the blanks in the following sentances:
(i). Two atoms of the same element combine to form a molecule. The bond between them is known as____ bond
(ii). Two chlorine atoms combine to form a molecule. The bond between them is known as_____
(iii). In forming oxygen molecule_____electrons are shared by each atom of oxygen.
(iv). In forming `N_(2)` molecule,_____electrons are shared by each atom of nitrogen.
(v). The number of siingle covalent bonds in `C_(2)H_(2)` molecule are______
(vi). Melting points and boiling points of ionic compounds are generally______than those of covalent compounds.