Among the elements Na, Ca, Al, K, Mg, and Li, which belong to the same period in the periodic table ?

Consider the following elements: Na, Ca, Al, K,Mg, Li (a) Which of these elements belong to the same period of the periodic table? (b) Which of these elements belong to the same group of the periodic table?

Which group of elements belong to the same period in periodic table :-

The elements with the same valence shell belong to the same period of the periodic table.

(a) What is common in the elements belonging to the same period in the periodic table ? (b) Why are chlorine and bromine kept in the same group in the periodic table ?

An element which lies in the same group of the periodic table as mercury is