Tag: Elemental abundance

With an average concentration of only about 90 parts per billion in the Earth's crust, selenium is indeed one of the rarer elements, found in three to seven orders of magnitude less abundance than major rock-forming elements. While it is a naturally occurring element, its rarity in significant concentrations means it is almost never mined directly.

While water is the most abundant nutrient in the human body, comprising roughly 60% of our total weight, the next most significant component is a fundamental element. The answer to the question "what is the second most abundant nutrient in the body?" is carbon, which forms the core structure of all organic molecules and makes up about 18% of our body's mass.