# Chapter 22 - Chemistry of the Main-Group Elements II: Groups 18, 17, 16, 15, and Hydrogen - 22-6 Concept Assessment - Page 1015: 22-6

The $\mathrm{Cl}$ atom is smaller than the $\mathrm{Br}$ atom. As a result, the central P atom can accommodate only four $\mathrm{Br}$ atoms, as in the tetrahedral $\mathrm{PBr}_{4}^{+}$ ion. However, the central $P$ atom can accommodate four $\mathrm{Cl}$ atoms in case of the tetrahedral $\mathrm{PCl}_{4}^{+}$ ion or six in case of the octahedral $\mathrm{PCl}_{6}^+$ ion.