Question

Classify each of the following on the basis of their atomicity:
(a) $F_2$
(b) $N{O}_2$
(c) $N_{2}O$
(d) $C_2{H}_6$
(e) $P_4$
(f) $H_2{O}_2$
(g) $P_4{O}_{10}$
(h) $O_3$
(i) $HCl$
(j) $C{H}_4$
(k) $He$
(l) $Ag$

Answer 1

(a) Atomicity is the total number of atoms present in a molecule or compound.
$F_2$ has 2 atoms of fluorine.
Therefore, fluorine $F_2$ is a di-atomic molecule.

(b) Atomicity is the total number of atoms present in a molecule or compound.
$N{O}_2$ has 1 atom of nitrigen and 2 atoms of oxygen.
Therefore, nitrogen dioxide $N{O}_2$ is a tri-atomic molecule.

(c) Atomicity is the total number of atoms present in a molecule or compound.
$N_{2}O$ has 1 atom of oxygen and 2 atoms of nitrogen.
Therefore, nitrous oxide $N_{2}O$ is a tri-atomic molecule.

(d) Atomicity is the total number of atoms present in a molecule or compound.
$C_2{H}_6$ has 2 atoms of carbon and 6 atoms of hydrogen.
Therefore, ethane $\left(C_2{H}_6\right)$ is an octa-atomic molecule.

(e) Atomicity is the total number of atoms present in a molecule or compound.
$P_4$ has 4 atoms of phosphorous.
Therefore, tetra phosphorous $P_4$ is a tetra-atomic molecule.

(f) Atomicity is the total number of atoms present in a molecule or compound.
$H_2{O}_2$ has 2 atoms of H and 2 atoms of O, so its atomicity is 4.
Therefore, hydrogen peroxide $\left(H_2{O}_2\right)$ is a tetra-atomic molecule.

(g) Atomicity is the total number of atoms present in a molecule or compound.
$P_4{O}_{10}$ has 4 atoms of phosphorous and 10 atoms of oxygen.
Therefore, $P_4{O}_{10}$ is a polyatomic molecule.

(h) Atomicity is the total number of atoms present in a molecule or compound.
$O_3$ has 3 atoms of oxygen.
Therefore, $O_3$ is a tri-atomic reaction.

(i) Atomicity is the total number of atoms present in a molecule or compound.
$HCl$ has 1 atom of hydrogen and 1 atom of chlorine.
Therefore, hydrogen chloride $\left(HCl\right)$ is a diatomic molecule.

(j) Atomicity is the total number of atoms present in a molecule or compound.
$C{H}_4$ has 1 atom of carbon and 4 atoms of hydrogen.
Therefore, $C{H}_4$ is a penta-atomic molecule.

(k) Atomicity is the total number of atoms present in a molecule or compound.
Helium $\left(He\right)$ is a mono atomic gas as noble gases do not combine and exist as mono atomic molecules.
Therefore, $He$ is a mono-atomic.

(l) Atomicity is the total number of atoms present in a molecule or compound. Metals don't have a simple structure but consists of very large and indefinite number of atoms bonded together. Hence, atomicity of all metals is considered as 1.
Silver $\left(Ag\right)$ has one atom of silver.
Therefore, $Ag$ is mono-atomic.