Question

Which of the following is a diatomic element?
A. Bromine
B. Iodine
C. Nitrogen
D. All of the above

Answer 1

Hint: Atomicity of a molecule is defined as the number of atoms that constitute a molecule. On the basis of atomicity, molecules can be classified as monatomic, diatomic, triatomic and polyatomic. Diatomic element or molecule is composed of two atoms of the same element.

Complete step by step solution:
We know that atomicity is the number of atoms that constitute a molecule. Diatomic element is composed of two atoms of the same element or we can say that it has atomicity of 2.
Bromine exists as \[\text{B}{{\text{r}}_{\text{2}}}\] so, we can say that it consist of 2 atoms of same element i.e. of bromine. Therefore, its atomicity is 2 and it is a diatomic element.
Iodine exists as ${{\text{I}}_{\text{2}}}$ , so its atomicity is 2 and it is a diatomic element.
Similarly nitrogen also exists as ${{\text{N}}_{\text{2}}}$ and its atomicity is also 2. So, it is a diatomic element.
So, we can say that bromine, iodine, and nitrogen all are diatomic elements. Therefore, option D is correct.

Additional Information: On the basis of atomicity elements are classified as:
1. Monoatomic: That is composed of 1 atom of the same element.
2. Diatomic: That are composed of 2 atoms of same element
3. Triatomic: That are composed of 3 atoms of same element
4. Polyatomic: That is composed of more than 3 atoms of the same element.
Note: There are five elements in the periodic table which are diatomic elements and exist in the form of gas at room temperature. They are hydrogen, nitrogen, oxygen, fluorine, and chlorine. If there is slight increase in temperature two additional elements bromine and iodine also exist as diatomic gas.