Element

      There are 118 elements, but only 92 occur naturally. The remaining elements have only been made in laboratories and are unstable.Gold, for instance, is an element, and so is carbon. 

       Each element is designated by its chemical symbol, which is a single capital letter or, when the first letter is already “taken” by another element, then a combination of two letters is there. Some elements have the English term for the element, such as C for carbon and Ca for calcium. And some elements have the Latin term for the element; for example, the symbol for sodium is Na, which is a short form of Latin word natrium, this Latin word is used for sodium.

      The four elements common to all living organisms are oxygen (O), carbon (C), hydrogen (H), and nitrogen (N) called Carbohydrates which together make up about 96% of the human body. In the nonliving world, elements are found in different proportions, and some elements common to living organisms are relatively rare on the earth as a whole.