Question

Is hydrogen stable or unstable?

Answer 1

Hint:Hydrogen is the first element of the periodic table and its atomic number is 1 which means there is only 1 electron in its outermost shell and this one-electron easily forms a bond with other atoms.

Complete step-by-step answer:We usually define the reactivity of any compound or element by its stability. If the compound or element is stable it will be least interesting to react with other elements, but if the compound is unstable then till will donate, gain, or share its electrons from the elements to form a compound so that it can become stable or inert.
Hydrogen is the first element on the periodic table and its atomic number is 1 which means there is only 1 electron in its outermost shell. So, it is placed in group 1 with alkali metals and in period 1and its electronic configuration is $1{{s}^{1}}$. This is a very unstable configuration.
For hydrogen and helium, the most stable compounds are formed when they have 2 electrons, since the hydrogen has only one electron, and it immediately forms a covalent or ionic bond. It forms an ionic bond by donating its one electron and it forms a covalent bond by sharing its one electron with other non-metals.
So, due to its capability of forming numerous compounds easily with its and other atoms, it is considered unstable.

Note:We know that there are three isotopes of hydrogen: protium, deuterium, and tritium. In which the protium and the deuterium are quite stable in nature. But the tritium is very unstable and found in traces.