. WHAT IS COVALENT BOND
A covalent bond is formed by the sharing of a pair of electrons between two atoms, each atom contributing one electron to the shared pair. The shared pair of electrons should have opposite spins and they are localized between the two nuclei concerned. A covalent bond is usually represented by a short line (i.e., a dash) between the two atoms. Note that the covalent bond consists of a pair of electrons shared between two atoms, and occupying a combination of two stable orbitals, one of each atom; the shared electrons of each covalent bond are counted for each of the two atoms connected by the covalent bond.