According to the context, 'the atoms within the square brackets form a single entity which does not dissociate under the reaction conditions.' The complex [Co(NH₃)₆Cl₂] should be interpreted as [Co(NH₃)₆]Cl₂, where [Co(NH₃)₆]²⁺ is the complex ion (coordination number 6) and 2 Cl⁻ are counter ions outside the coordination sphere. In solution, this produces 3 ions total: 1 complex ion [Co(NH₃)₆]²⁺ and 2 chloride ions Cl⁻. This follows the pattern shown in Table 5.1, where complexes like [CoCl₂(NH₃)₄]⁺Cl⁻ produce 2 ions (1:1 electrolyte), [CoCl(NH₃)₅]²⁺2Cl⁻ produce 3 ions (1:2 electrolyte), and [Co(NH₃)₆]³⁺3Cl⁻ produce 4 ions (1:3 electrolyte).