The lattice energy of an ionic compound depends on which of the following?

Favourable conditions for electrovalency are

Which of the following compounds contains both ionic and covalent bonds?

The force which holds atoms together in an electrovalent bond is

Which combination forms the strongest ionic bond?

For ionic solids,choose the correct option using $T$ (True) or $F$ (False) for the following statements:
$(1)$ They have very high melting and boiling points.
$(2)$ They are electrolytes.
$(3)$ They possess directional bond characteristics.
$(4)$ They can have isomorphic types of structures.