Write the atomic number of the element present in the third period and seventeenth group of the periodic table.





Q.6:- Write the atomic number of the element present in the third period and seventeenth group of the periodic table.

 

 

Answer:-

There are two elements in the 1st period and eight elements in the 2nd period., The third period starts with the element with Z = 11(sodium). Now, there are nine  elements in the third period. Thus, the 3rd period ends with the element with Z = 18(argon) i.e., the element in the 18th group of the third period has Z = 18. Hence, the element in the 17th group of the third period has atomic number Z = 17 ,chlorine(Cl) with atomic mass 35.453, which is a p block element.