Charactristics of the atomic structure of helium

Question1. In modern blimps, the gas of choice used to inflate them is helium rather than hydrogen. Hydrogen would be lighter, but helium is safer. Compare and contrast the atomic structure of hydrogen and helium. What charactristics of the atomic structure of helium make it so much less reactive than hydrogen?

Question2. Amino acids are the buiding blocks of proteins. Less than a dozen amino acids make up most of our proteins. explain how so few amino acids are responsible for the billions of proteins that are used by the body.

Question3. How would you contrast sinle covalent bonds, double covalent bonds, and ionic bonds?