Question

What is the difference between $2H$ or ${{H}_ {2}}$?

Answer 1

Hydrogen bonding takes place when any atom goes through dipole-dipole interaction of a very electronegative atom. Complete answer: Differences between $2H$ and $H_2$ are given in the below table:

$2H$	${{H}_ {2}}$
$2H$ molecules tell us about the 2 molecules of hydrogen which are formed when the both hydrogen atoms get bonded together.	Hydrogen molecules take us about only one molecule of the hydrogen which gets formed when 2 different hydrogen atoms make then bonding together.
$2H$ are considered to be the molecular hydrogen which is considered to be present in trace amounts in the atmosphere. The molecular hydrogen acts as an antioxidant and also protects the cell. We can inhale hydrogen only at low concentration.	${{H}_ {2}}$ is considered as the atom hydrogen where if there is a single the charge proton and electrons gets attached to the molecules of the electrically neutral atom by the constant force and it provide about 75% of the universe mass.
($2H$) have 2 free radicals within it and are mostly found in the plasma uric acid. They also occur in the low temperature and get degenerated at high temperature.	(H) without any change is considered as free radical, which occurs in the low temperature and the high temperature the existence of hydrogen is very short.
$2H$ clearly represent 2 different hydrogen molecules that are independent of each other and there is no chemical bonding or any other force of attraction between them too.	This ${{H}_ {2}}$ molecule helps in the arrangement of a great number and forms 2 hydrogen atoms with a covalent bond and also Vander Waal force exists between the 2 of hydrogen molecules.
$2H$ consists of$2H$ atoms of hydrogen which are not banded with each other. The $2H$ molecule of hydrogen may contain 1 +ve or a -ve change after it.	${{H}_ {2}}$is considered as a diatomic molecule of hydrogen which is composed of 2 atoms of the same or some different elements. These types of elements are also termed as Homonuclear.

Note: Most of the times the bonding between the Hydrogen occurs only with Fluorine, oxygen and nitrogen constituting F O N- elements.