Question

Molecules are held together by _ _ _ _ _ _.
(A)- covalent bond
(B)- ionic bond
(C)- both A and B
(D)- none of above

Answer 1

Hint: The atoms in the molecule are held together depending on the electronegativity difference of the constituent atoms and the electrostatic attraction thus produced on which the type of chemical bonding will be determined.

Complete step by step solution:
A molecule having two or more atoms present in it, such that the atoms have a lasting attraction which holds them together. It leads to the formation of the chemical bond. This is due to the tendency of the atoms present in the molecule to complete its octet, which is the most stable arrangement possible. Thus, forming a bond with the neighbouring atoms through chemical bonding to form the molecule.
The two main types of chemical bonds depending on the electronegativity difference of the constituent atoms are as follows:
- The Ionic bond has the difference in the electronegativity of the constituent atoms such that two separate ions (cation and anion) are formed, by the gain of electron by one atom and the loss of electron by the other. Thus, having an electrostatic force of attraction between them which forms the ionic bonding.
- The Covalent bond, rather than the transfer of electrons, involves the sharing of the valence electrons between the two atoms, having minimal difference in their electronegativity. Thus, forming the bond, with one electron from each atom in the bond pair. Thus, there is an equilibrium between the force experienced by the atoms in the covalent bonding.
Therefore, in the molecules the bond present may be ionic or covalent depending on the difference in the electronegativity of the atoms.

So, the molecules are held together by option (C)- both A (covalent bond) and B (ionic bond).

Note: The two types of chemical bonds are the strongest intramolecular bonds. The intermolecular bonds are also present like the dipole-dipole interaction, hydrogen bonding and the London dispersion force.