The correct option is H - H
Compare to other type of bonds given above, the hydrogen to hydrogen bond is very unreactive. This is because the bond is very stable. Each of the hydrogen atom in the bond donate their single electron to form a covalent bond, which is quite stable.
Yes the ANSWER is Correct-
On first half life the mass will be 10 gram
On second half life the mass will be 5 gram
On third half life the mass will be 2.5 gram