Question

 How does the tendency to gain electrons change as we go down in group 17 of the periodic table? Why does it change this way?

 

Answer 1

In group 17 of the periodic table, the tendency to gain electrons decreases on moving from top to bottom. On moving down in a group, an electron shell gets added at every stage. As a result, the atomic radius increases. Since the size of the atom goes on increasing, it becomes difficult for the nucleus to attract the incoming electron, due to which the atom cannot form anions easily.