Question

Which of the following bonds is the strongest?
(A) $F - F\,$
(B) $I - I$
(C) $H - H$
(D) $O - O$

Answer 1

As we know that the bond is formed by the sharing of electrons of two atoms of same electronegativity. The strength of this sharing depends upon the outer most electronic configuration of the atoms which are taking part in the bond formation.

Complete step by step answer:
As we move from left to right in the periodic table, we find that the number of electrons increases and size of atoms decreases. This leads towards more repulsion and due to the repulsion, the electrons move away and the strength of bonding decreases.
As we move from top to bottom in a period, the size of orbitals increases hence the electrons are not so stable to form bonds.
Let’s we find the answer from the above explanation,
In the option (A), the fluorine gas is found at extreme right in the periodic table, so the size of the fluorine atom is very small and electron crowding is large so when to fluorine atom come together to form bond, they feel repulsion with each other due to excess electron crowding. Therefore, the strength of bonding is weak.
In option (B), iodine is the ${4^{th}}$element of the halogen group. As we know that when we move from top to bottom size increases so the bonding between iodine gases is very weak.
In the option (C), hydrogen is the first element of the periodic table it has only one electron and the size of hydrogen is also small, so to complete the octet, the hydrogen atoms approach each other and form bonding with maximum strength.
In the option (D), oxygen also is found on the right in the periodic table so the bonding between the oxygen is also weak.

The correct option is C.

Note:
The bonding between the same atoms depends upon several properties as size, electronegativity, number of bonds etc.