Final answer:
The bond joining two hydrogen atoms is a covalent bond, characterized by the sharing of electron pairs between atoms. Monosaccharides form polysaccharides through glycosidic bonds, which are also a type of covalent bond.
Step-by-step explanation:
The type of bond joining the two hydrogen atoms in a molecule of hydrogen gas (H2) is a covalent bond. Each hydrogen atom in the molecule shares one electron with the other, resulting in a pair of electrons being shared between the two atoms. This type of electron sharing is characteristic of covalent bonding, which is a strong type of bond where atoms are held together by shared electrons. It's different from ionic, hydrogen, or polar covalent bonds.
In the case of monosaccharides linking together to form polysaccharides, the bond that forms between them is known as a glycosidic bond. Glycosidic bonds are also a type of covalent bond that occurs specifically between carbohydrate molecules.