Classify each of the following on the basis of their atomicity:
$(a) F_2$
$(b) NO_2$
$(c) N_2O$
$(d) C_2H_6$
$(e) P_4$
$(f) H_2O_2$
$(g) P_4O_{10}$
$(h) O_3$
$(i) HCl$
$(j) CH_4$
$(k) He$
$(l) Ag$

(N/A) Atomicity is the total number of atoms present in one molecule of an element or compound.
$(a) F_2$: Diatomic ($2$ atoms)
$(b) NO_2$: Triatomic ($3$ atoms)
$(c) N_2O$: Triatomic ($3$ atoms)
$(d) C_2H_6$: Octatomic ($8$ atoms)
$(e) P_4$: Tetratomic ($4$ atoms)
$(f) H_2O_2$: Tetratomic ($4$ atoms)
$(g) P_4O_{10}$: Polyatomic ($14$ atoms)
$(h) O_3$: Triatomic ($3$ atoms)
$(i) HCl$: Diatomic ($2$ atoms)
$(j) CH_4$: Pentatomic ($5$ atoms)
$(k) He$: Monoatomic ($1$ atom)
$(l) Ag$: Polyatomic (Metals exist as a giant lattice structure containing a large number of atoms).