Question

Which is the longest group in the periodic table?

Answer 1

In a modern periodic table, which consists of $18$ groups has a different number of elements in these groups. To find out which group is longest or contains the maximum number of elements simply count the number of elements vertically.

Complete answer:
In a modern periodic table the physical and chemical properties of the elements are periodic functions of their atomic numbers. There are a total $18$ number of groups.
Elements in the same vertical column or group have a similar number of valence shell electronic configuration, the same number of electrons in the outer orbitals, and similar properties. Group numbers from $1,2$ and $13 - 18$ are together called representative elements and from $3 - 12$ are called representative elements.
Now to answer the question let’s check out the number of elements in each group. We can clearly conclude that in a group $1$ there are seven numbers of elements which are $H,Li,Na,K,Rb,Cs,Fr$ . While the rest of the group has either six or four numbers of elements. Therefore our answer is Group $1$ has the maximum number of elements and therefore the largest or longest group in the periodic table.
Let’s learn a little bit about the Group $1$ elements. They are called the alkali metals because on reaction with the water they form alkali metals. They have the outermost electronic configuration as $n{s^1}$ . They are reactive metals with low ionization enthalpies. They lose the outermost electron readily to form the ${1^ + }$ ion. Their metallic character increases as we go down the group which means they become more metallic as we move vertically the periodic table.

Note:
The elements of the alkali metals as well as the alkaline metal which form the $s$ block elements are never found pure in nature as they are highly reactive in nature. Also the compounds of $s$ block elements are predominantly ionic except $\;Lithium$ and $Beryllium$