Question

Find the atomicity of the following molecules:
1.${{\text{H}}_{\text{2}}}$
2.${{\text{O}}_{\text{2}}}$
3.$\text{HCl}$
4.$\text{NaOH}$
5.$\text{CaC}{{\text{O}}_{\text{3}}}$
6.${{\text{P}}_{\text{4}}}$
7.$\text{C}{{\text{a}}_{\text{3}}}{{\left( \text{P}{{\text{O}}_{\text{4}}} \right)}_{\text{2}}}$

Answer 1

Hint: The atomicity of an element can be defined as the number of the atoms present in the molecule of the element. It is only calculated for homoatomic molecules.

Complete Answer:
1.Hydrogen molecule – The molecule of hydrogen has two atoms and hence its atomicity is equal to two.
2.Oxygen molecule - The molecule of oxygen has two atoms and hence its atomicity is equal to two.
3.Hydrogen Chloride – Not applicable because this is a compound not an element.
4.Sodium Hydroxide – Not applicable because this is a compound not an element.
5.Calcium Carbonate – Not applicable because this is a compound not an element.
6.Phosphorus – In one molecule of phosphorus, there are four atoms of phosphorus. Hence its atomicity is four.
7.Calcium Phosphate - Not applicable because this is a compound not an element.

Notes: The atomicity of the element can range from 1 to n. The metals and the noble gases are always monoatomic. The gases besides the noble gases are all diatomic containing two atoms in the molecule. The ozone gas is triatomic. Phosphorus is tetratomic containing four atoms in the molecule. Sulphur is octatomic containing eight atoms in a molecule. The buckminsterfullerene or the buckyballs contain about 60 carbon atoms and can go upto 70 carbon atoms also. This allotrope of carbon was discovered quite recently by Curl, Kroto, and Smalley in the year 1996 and were also awarded the nobel prize for this in the same year.