You would be amazed at what can be insured. Specifically to your point, some investments are insured against down side exposure. The easiest example is private mortgage insurance. If you buy a home...
Some elements have one because they are only based on one pure element. Like Hydrogen, we can get that from the air. Make sense?
There are different properties of each element that make them all different. Hardness and softness are one of the physical properties.
Argon,hydrogen,uranium,helium
one for sure is Iodine