MindMap Gallery helium
This is a mind map about helium. Helium (Helium), with the element symbol He and atomic number 2, is the second most abundant element in the universe (after hydrogen), but its content is very rare on the earth. Helium is a colorless, tasteless and odorless inert gas with very stable chemical properties and almost no chemical reaction with other elements.
Edited at 2024-10-28 19:03:44