Identify the group 3A element that best fits each of the following descriptions.

(b) Is stable in the +1 oxidation state

Video transcript

All right. Hi, everyone. So this question is asking to identify whether the following statement is true or false gallium is the most stable in the positive one oxidation state among three A elements. Now excluding the trans aides and the much heavier elements, the group three A elements consist of boron aluminum gallium, indium and thallium. Right? So what I've done on the screen here is the list them going from top to bottom in the group itself or the column in this case. Now, this statement is actually false because recall that most of the three A elements are stable with an oxidation state of plus three of all the three A elements only thallium is stable in the positive one oxidation state, whereas the others remain stable with an oxidation state of positive three. And recall that the reason for this is due to a phenomenon known as the inert care effect. Now recall that the inert paar effect is present more so in heavier elements of a given group. And it's described as the tendency of the two electrons in the outermost s orbital, the outermost as orbital to remain unshared. In other words, right, the inner pa effect describes a phenomenon observed in heavier elements in which their outermost s orbital electrons do not tend to participate in bonding. And so the primary reason, or one of the reasons, at least for the inert pair effect is because as you go down a group or you go down a column in the periodic table bond energies tend to decrease as you go downwards. So because thallium is the bottommost element of the ones listed in group three A, it is the only one considered stable due to the inert pair effect, resulting in an oxidation state that is too less than the expected oxidation state of that group. So in this case, it is positive one as opposed to positive three, which means that overall, the statement proposed in the question is going to be false. So with that being said, thank you very much for watching and I hope you found this helpful.