3 ms·

Likely some combination of abundance and electronegativity. For instance, from your example - Sodium is about a zillion times more abundant than Lithium https:

• mcv 3y ago
  Nice graph. But if I understand it correctly, Chloride is about as abundant as Lithium, and less abundant than its neighbours Sulfide, Phospor, Fluoride etc. So why is chloride so abundant in the ocean? Sodium makes sense, but chloride does not. I'm also surprised to see that Nitrogen is relatively rare compared to its neighbours Carbon and Oxygen, despite making up 80% of the atmosphere. Or maybe that's why? Are we losing nitrogen to space?
  • pvg 3y ago
    The 'electronagativity' was a handwave for 'the chemical and physical properties of the element'. E.g. the solubility of its salts or other compounds in water, processes that cycle or collect it elsewhere, etc. Nitrogen is less reactive than Oxygen, doesn't form as many compounds as Carbon and has a molecule too fat to easily escape into space.