perhaps it should not have so suprising to carbon based life forms(such as human beings) that the sixth element in the periodic table has such remarkable propetties. After all, carbon, one of the most unbiquitous kinds of atoms on Earth had long been known to exist as a solid in two very different forms: soft, black graphite (pencil lead) and ultrahard, transparent diamond. In combination with other elements it was also known: carbon forms more than a million compounds-more than all other elements combined. A few carbon-based compounds are gases in air(such as carbon dioxide), several more are solids in roxks (such as the calcium carbonate that is limestone) and tens of thousands are in living cell( as carbohydrates, proteins, fats and DNA)
การแปล กรุณารอสักครู่..
