What is the most common oxidation state for each of the

group 3A elements?

Video transcript

Alright. Hi, everyone. So for this question, determine the most common oxidation states for each of the following elements, boron aluminum gallium Indian. And sadly, so here we've got four different answer choices. Each one proposing different oxidation states for all five elements listed ranging from positive four to positive one. So let's go ahead and get started. Right. Recall that generally speaking, right, the majority of group three A elements including the ones listed here are stable with an oxidation state of plus three or positive three. However, there is an exception and that exception happens to be thallium because thallium being the heavier element of those in group three A exhibits what's known as the inert. Perfect, meaning that it's going to be stable at an oxidation state that is too less than the typical oxidation state for that group. So what that means is that Valium being the exception is generally stable with an oxidation state of positive one instead, now the inner pair effect as I discussed previously is an effect that's generally observed among heavier elements within a given group. And the reason for this is because heavier elements demonstrate a tendency for the two electrons in the outermost S orbital to remain unpaired. In other words, for heavier elements, the two electrons in the outermost s orbital don't excuse me, do not tend to participate in bonding. And this effect increases as you go down a group, meaning as you approach the heavier elements. Now, the reason for this or one of the reasons at least is that bond energies decrease as you go down a group in the periodic tape. So of all of the elements listed thallium is the only one considered stable at an oxidation state of positive one. Whereas the remaining four are stable at an oxidation state of positive three, which means that our answer is going to be option B in the multiple choice because the most common oxidation states for boron aluminum gallium and indium are positive three. Whereas for thallium, it is positive one. So with that being said, thank you very much for watching and I hope you found this helpful.