Question

What are ionic and molecular compounds? Give examples.

Answer 1

Hint: Atoms are held together by chemical bonds that make up a molecule. Compounds are classified according to the bonds present in them. These bonds can be formed by the transfer of electrons between atoms, or the sharing of the electron pairs between atoms. The electronegativity differences between atoms also affect the nature of bonds.

Complete answer:
A chemical compound consists of atoms that are held together through various types of chemical bonds. The nature of the formation of these bonds decides the type of compounds. They are classified as ionic or molecular (covalent) compounds.
-Ionic compounds are formed when the atoms consist of a metal and a non – metal that is having a large difference in electronegativities. The metal is able to donate the valence electron to form a cation (positive ion) and the non – metal accepts this electron and forms an anion (negative ion). So, the transfer of electrons from a metal to a non – metal results in ionic bonds and the compounds are called ionic compounds.
Examples of ionic compounds are sodium chloride NaCl, potassium chloride KCl, calcium oxide CaO, etc.
-Molecular compounds also called covalent compounds consist of atoms having almost similar electronegativities. Therefore, in these compounds the valence electrons of the atoms are shared with the other atoms that form covalent bonds and the compounds are called molecular or covalent compounds.
Examples of molecular compounds are water $H_{2}O$, methane $C{H}_4$, carbon dioxide $C{O}_2$, etc.
Hence, the ionic and molecular compounds have transfer and sharing of electrons respectively.

Note:
There are various types of forces in ionic and molecular compounds in the formation of bonds. Ionic compounds have strong electrostatic forces in their bond formation, while molecular compounds have 3 types of forces, weak dispersion, dipole – dipole forces and hydrogen bonding. Hydrogen bonds are formed between hydrogen and electronegative atoms like F, O, N.