Question

How many pairs of electrons are shared by the two atoms having (a) single (b) double (c) triple, bond between them?

Answer 1

H(a) single bond:

1. Single bond is a type of chemical bond between two atoms involving two valence electrons.
2. In single bond one pair of electrons(two electrons) is shared, with one electron being contributed from each of the atoms.
3. Example: Formation of Hydrogen molecule $(\mathrm{H}-\mathrm{H})$
4. Hydrogen contains 1 valence electron, so two Hydrogen atom share their 2 valence electron to form a single bond.

(b) double bond:

1. Double bond is a type of chemical bond in which four electrons are shared between two atoms in a molecule.
2. In a double bond two pairs of electrons (four electrons) are shared between two atoms.
3. Example: Formation of Oxygen molecule $(\mathrm{O}=\mathrm{O})$
4. The atomic number of Oxygen is 8.
5. The electronic configuration is 2, 2, 4. Therefore, 6 valence electrons are present.
6. Each Oxygen atom shares it 2 electron to form double bond and 4 electrons are present around Oxygen as lone pairs.

(c) triple bond:

1. Triple bond is a type of chemical bond in which six electrons are shared between two atoms in a molecule.
2. In a triple bond three pairs of electrons (six electrons) are shared between two atoms.
3. Example: Formation of Ethyne( $\mathrm{CH}\equiv \mathrm{CH}$)
4. The atomic number of Carbon is 6.
5. The electronic configuration is 2, 4.
6. The valence electrons is 4.
7. The two Carbon atom shares 3 electrons each to form triple bond and 1 electron each is shared with two Hydrogen to form single bond.