CBSE Class 10 Science 2022 · Paper 31(B)/5 · Question 1(a)

Covalent compounds are compounds in which the atoms are held together by covalent bonds, that is, by sharing pairs of electrons between atoms; no electrons are transferred and no ions are formed. Examples: methane (${\text{CH}}_4$), water (${\text{H}}_2\text{O}$), ethanol (${\text{C}}_2{\text{H}}_5\text{OH}$). Two properties of covalent compounds: 1. They generally have low melting and boiling points, because the forces of attraction between their molecules are weak (the bonds within each molecule are strong). For example, methane melts at $90$ K and boils at $111$ K. 2. They are generally poor conductors of electricity, because they contain no ions (charged particles) to carry the current.