"What are the most stable chlorides of Gallium and Thallium. Explain your answer in terms of Zeff.
Zeff = Z - S
Z = number of protons
S = number of core electrons
The Attempt at a Solution
Well my attempt at a solution is that GaCl3 and TlCl3 are the most stable chlorides of Ga and Tl. Ga has 31 protons and 28 core electrons so Zeff = 31 - 28 = +3 valence electrons (4s24p1). The same also applied for Thallium so Zeff = 81- 78 = +3 valence electrons (6s26p1). So Ga+3 and Cl-1 = GaCl3 and Tl+3 and Cl-1 = TlCl3