How was the Periodic Table of Elements developed and how are the elements arranged on it?

Following are the solution to this question:

Explanation:

Mendeleev has been the chemist that designed a periodic table for component identification based on the increasing number of elements. Thus, the is traditionally called a table parent and this periodic table had some drawbacks.

Consequently, Mosley rebuilt Mendeleev's periodic table to once again overcome this disadvantage. Which atoms were arranged as per the increasing order of atomic number instead of mass number. The traditional table, therefore, comprises seven horizontal lines regarded as cycles. But 18 control limits were named group lines.

The whole Periodical Tables is classified as a,p,d, and f block

S block, groups have 1 and 2.

P block, group has 13-18  

D block, group has 3 to 12

F block, – Two lines far below the periodic table.

the answer is d.) potassium