Question

What is the atomicity of ${{O}_{3}}$?

Answer 1

Generally, atomicity can be described as the number of atoms present in one molecule of an element. Based on atomicity a molecule can be monatomic, diatomic, triatomic etc. Ozone (${{O}_{3}}$) is a triatomic molecule which consists of three oxygen atoms.

Complete step by step solution:
-As we know, ozone is a triatomic molecule of oxygen with the chemical formula ${{O}_{3}}$. It's another form of oxygen element.
-Let's look at the concept of atomicity. It can be explained as the total number of atoms present in a molecule. For example, oxygen gas exists as diatomic oxygen in the atmosphere. It consists of two oxygen atoms and hence the atomicity of ${{O}_{2}}$ is two.
-Similarly, the atomicity of ozone can also be determined. One molecule of ozone consists of three oxygen atoms and hence the atomicity of the ozone molecule is three. Or else we can say that ozone is a triatomic molecule.
-The atomicity of ozone can be found from an alternative method. The ratio of the molecular mass of ozone to the atomic mass of ozone will give us the number of oxygen atoms in ozone and thus we can find out the atomicity of ${{O}_{3}}$. This can be represented as follows,
$Atomicity=\dfrac{Molecular\text{ }mass\text{ }of\text{ }ozone}{Atomic\text{ }mass\text{ }of\text{ }ozone}$
As we know the atomic mass of oxygen is 16 g and the molecular mass of ozone will be three times the atomic mass of atomic oxygen. That is the molecular mass of ozone is 48g (16×3).
Substituting this in the above equation we get,
$Atomicity=\dfrac{48g}{16g}$
$=3$

Therefore, the atomicity of ozone (${{O}_{3}}$) is three.

Note: Keep in mind that ozone is a homonuclear molecule since it contains only one type of atoms. Thus, in simple homonuclear molecules like this, we could just count the number of atoms and can find the atomicity. But in the case of heteronuclear molecules which contain more than one type of atoms, use the second method to find atomicity in which the ratio between molecular mass and atomic mass is found.