• Question: Are there any non-synthetic elements that we could live without?

    Asked by ogoldfinch09 to Laura, Lena, Sean on 21 Mar 2012.
    • Photo: Sean Murphy

      Sean Murphy answered on 21 Mar 2012:

      Of the 100 plus known elements, two to three dozen can be found in most organisms. Most are found in trace amounts, but five stand out: carbon, hydrogen, oxygen, nitrogen and phosphorus.

      For life *as we know it*:

      Oxygen (65%)
      Carbon (18%)
      Hydrogen (10%)
      Nitrogen (3%)
      Calcium (1.5%)
      Phosphorus (1.0%)
      Potassium (0.35%)
      Sulfur (0.25%)
      Sodium (0.15%)
      Magnesium (0.05%)
      Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%)
      Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts).

      This leaves others that we could live without (perhaps), but are currently used for things like computers/iPhones, such as rare earth elements http://en.wikipedia.org/wiki/Rare_earth_element

    • Photo: Lena Ciric

      Lena Ciric answered on 21 Mar 2012:

      Yes. Humans only need about a quarter of the elements that we have here on Earth to live. But we have been very good at exploiting what we find around us. You could argue that many other elements are essential for us to live the way that we do in the modern world. Neither gallium nor germanium are essential for life but they are widely used around the world. Gallium compounds are major constituents of different semiconductors. Germanium is widely used in fiber-optics and infrared optics.