Question

Classify the following based on atomicity.
Chlorine
Neon
Phosphorous
Ozone

Answer 1

Hint: To classify the elements in the given, we look into the general definition of atomicity. Then we write down all the given elements in their atomic forms, i.e. we represent the given elements in their respective molecular forms and find out their respective atomicity.

Complete step by step answer:
The given elements in their molecular form are Chlorine ${\text{C}}{{\text{l}}_2}$
Neon Ne
Phosphorus P
And Ozone ${{\text{O}}_3}$.
This means that the given elements, for example chlorine exists in a stable state by itself only when two chlorine atoms combine and form a ${\text{C}}{{\text{l}}_2}$ molecule and follows.
Now atomicity means the number of atoms in a single molecule of an element, in its stable state.

Now atomicity of the following is:
Chlorine: ${\text{C}}{{\text{l}}_2}$, it is a diatomic molecule (contains 2 atoms). Its atomicity is 2.
Neon: Ne, it is a monatomic molecule (contains 1 atom). Its atomicity is 1.
Phosphorous: P, it is a monatomic molecule (contains 1 atom). Its atomicity is 1.
Ozone: ${{\text{O}}_3}$, it is a triatomic molecule (contains 3 atoms). Its atomicity is 3.

The molecule with only one atom is called a monatomic molecule, with two atoms it is a diatomic molecule and with three molecules it is a triatomic molecule.
Therefore, the given molecules are classified as followed:
Monoatomic – Neon (Ne) and Phosphorous (P)
Diatomic – Chlorine (${\text{C}}{{\text{l}}_2}$)
Triatomic – Ozone (${{\text{O}}_3}$)

Note: In order to answer this type of questions the key is to know the chemical representation of the stable molecular states of each of the given elements. That directly helps us figure out how many atoms the molecule has.
Alternatively, we can determine the atomicity of an element as the ratio of its molecular mass to its atomic mass.
Atomicity of an element =$\dfrac{{{\text{Molecular Mass}}}}{{{\text{Atomic Mass}}}}$.