When the first element of the periodic table is treated with dioxgyen , it gives a compound whose soilds state floats on its liquid state. This compound has an ability to act as an well as a base. What products will be formed when this compound undergoes autoionsation?

Explanation

The first element is hydrogen and its molecular form is dihydrogen `(H_2)`. It reacts with oxygen to form water whose solid state is ice which is lighter than water and floats over water.
Water is amphoteric in nature i.e., it acts as an acid in the presence of strong bases and acts as a base in the presence of strong acids. As an acid
`underset("acid")(H_2 O(l)) + underset("base")(NH_3(aq)) to NH_4^(+) (aq) + OH^(-) (aq)`
As a base
`underset("base")(H_2 O (l)) + underset("acid")(H_2 S(aq)) to H_3O^(+) + HS^(-)`
Due to amphoteric nature, water undergoes self ionization as
`H_2 O + H_2 O to H_3 O^(+) + OH^(-)`