Question

How do covalent bonds share electrons?

Answer 1

In the case of covalent bonds the sharing of electron pairs takes place between atoms. These electron pairs are called shared pairs or bonding pairs. Generally, the forces between atoms that is the stable balance of attractive and repulsive forces during sharing of electrons is known as covalent bonding.

Complete step by step answer:
There are various kinds of interaction in covalent bonding. Such as $\sigma - bonding$ , $\pi - bonding$, metal-to-metal bonding, agostic interactions, bent bonds, three-center two-electron bonds and three-center four-electron bonds.
In the molecule ${H_2}$ , the hydrogen atoms share the two electrons by covalent bonding. The atoms having almost similar electronegativity are able to form covalent bonds and they have highest covalency. So, the two atoms being of the same elements is not the compulsion for the formation of covalent bonds but they must have comparable electronegativity. Covalent bonding in which involvement of electrons over more than two atoms is called delocalized.
Except $s - orbital$ , atomic orbitals have specific directional properties leading to different types of covalent bonds. The most strongest type of covalent bond is $\sigma - bonds$ . They form by head-on overlapping of orbitals on two different atoms. A single bond is usually a $\sigma - bonds$ . $\pi - bonds$ are weaker and are due to lateral overlap between $p - orbital$ or $d - orbital$ . A double bond between two given atoms consists of one $\sigma$ and one $\pi - bond$ , and a triple bond is one $\sigma$ and two $\pi - bonds$ .

Note:
Covalent bonds also depend on the electronegativity of the connected atoms. Electronegativity also explains the chemical polarity of the bond. The atoms with the same electronegativity form nonpolar covalent bonds. For example $H - H$ . If two atoms have different electronegativity then they will form polar covalent bonds for example $H - Cl$ .