NEET-XI-Chemistry
03: Classification of Elements and Periodicity in Properties
- #6Write the atomic number of the element present in the third period and seventeenth group of the periodic table.
Ans : 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. Now, there are eight elements in the third period. Thus, the 3rd period ends with the element with Z = 18 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.