Question

Is lithium or hydrogen which one is representative element?

Answer 1

The Elements of the s-block are commonly called as the Representative elements.

Now, we know that Hydrogen and Lithium both lies in Alkali metals series of s-block thus they are Representative Elements.

Representative Elements are those elements which summarizes the properties of there Respective groups of the Periodic Table.

Now, we know that Hydrogen has lot of similarities with the Halogens also which lies in the p-block, thus position of hydrogen in uncertain in Periodic table.

Thus, It cannot be 100% said that Hydrogen is the Representative Elements because it does not exactly summarizes the properties of the Alkali metals.

But on the other hand Lithium summarizes the whole properties of the Alkali metals and used to represent them and also does no have any uncertainty in its positions.

Hope it helps.

Answer 2

In chemistry and atomic physics, the main group is the group of elements (sometimes called the representative elements) whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the periodic table of the elements.