Answer:
a. True
Explanation:
In the periodic table , all the elements are placed in a certain fashion , i.e. , with increasing atomic number.
Since ,
The element lithium and nitrogen are placed , in group 1 and 15 respectively.
as we go from left to right , across the group , the atomic radius decreases ,
Because ,
As , we go left to right , the number of electrons increases in the same shell , and proton too increases , which in turn increases the nuclear attraction , and the nucleus holds on to the electrons more firmly , and hence , the size reduces , as the electrons increases , in the same shell.
Hence, the given statement is true.