What is a terminal atom and why are hydrogen and the halogen elements considered terminal atoms?

Explanation:

Terminal atoms -

The atoms that are always present at the terminal position , because they have the capability of bonding via one single bond .

hence ,

Hydrogen atom is a terminal atom , because it can only form one single bond , since , hydrogen has only one electron in its shell , so the octet is completed by sharing that electron with another one electron , and forming a bond .

Therefore , hydrogen atom is considered to be a terminal atom .

Similarly , Halogens have 7 electrons , hence , to attain noble gas configuration , it require only one electron .Hence , it can form only one single bond .

Therefore ,  halogen atom is considered to be a terminal atom .

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