Question
A group of elements in the periodic table are given below.
(Boron is the first member of the group and Thallium is the last)
Boron, Aluminium, Gallium, Indium, Thallium
Answer the following questions in relation to the above group of elements :
(c) If the electronic configuration of aluminium is 2, 8, 3, how many electrons are there in the outer shell of thallium ?