One remedy for a deficiency of vitamin B12 for the elderly is a regular injection of this important nutrient. The vitamin B12 injection dose depends on factors such as gender and age.
Hydrogen bonds happen in alcohols. As a matter of fact, any molecule that contains a hydrogen atom attached to an atom of nitrogen or oxygen is capable of such a bond. Ethanol is one such alcohol that features hydrogen bonds. Ammonia is an example of hydrogen bonding. In the case of ammonia, however, the hydrogen bond happens to be relatively weak.
Hydrogen bonding occurs between a hydrogen atom and an electronegative atom (e.g., oxygen, fluorine, chlorine). The bond is weaker than an ionic bond or a covalent bond, but stronger than van der Waals forces (5 to 30 kJ/mol). A hydrogen bond is classified as a type of weak chemical bond.