Explanation
Hydrogen is the lightest element with 1 atomic mass unit , it is the first element in the first 20 elements in the periodic table, hydrogen exists in form of several isotopes . Hydrogen is found in combined form with other elements such as with oxygen to make up water and also in hydroxides
Hydrogen has an atomic number 1 and therefore has 1 proton and 1 electron . For hydrogen to become stable it can either gain or lose one electron since the energy needed in doing so is the same.In both cases it develops a valency 1 . If hydrogen gains one electron its ion becomes H– (forming an anion) this means it will behave as a halogen ( non -metal ) that becomes stable by gaining one electron. Example of halogen is Fluorine with atomic number 9 and hence electronic arrangement is 2,7 , this becomes stable by gaining one electron to form flouride ion (F-) – 2,8
On other hand , hydrogen can lose the one electron as the alkali metals (Group i ) to have it’s ion as H+ . When hydrogen loses it’s only electron it cation contains only one proton in the nucleus, 0 neutron and 0 electrons . Lithium is an alkali metals with atomic number 3 hence electronic arrangement is 2.1 and loses one electron in it’s last energy level to form the Li+ ion .
Therefore hydrogen become stable by either loosing one electron as the alkali metals or by gaining one electron as the halogens .
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