How Many Chemical Elements are There?
A chemical element is a type of atom, like hydrogen or oxygen. As of January 2007, 117 elements have been observed, with 94 of these elements occurring naturally on Earth. 23 elements are artificially created, in nuclear reactors or particle accelerator experiments. The first synthetic element to be created in substantial quantities was plutonium, element 94. Plutonium is also the heaviest atom found naturally on Earth. With a half-life of only 80 million years, plutonium occurs in extremely small quantities in uranium ores. The present-day chemical elements come from one of three sources: supernova nucleosynthesis, stellar nucleosynthesis, and Big Bang nucleosynthesis. Nucleosynthesis occurs when atomic nuclei pressed together so closely and at such high heat that they overcome the mutual repulsion of their electron shells and produce heavier nuclei. In this way, hydrogen nuclei can be fused into helium nuclei, which can in turn fuse into carbon nuclei, if conditions of sufficient tem
there are 118 “known” elements, although 9 or 10 of those have not even been made they just theoretical, ie fill gaps in the periodic table (they all begin with the prefix chemical symbol as Uu), only 92 occur naturally. we can synthesis the rest. Most of the man made one are pretty useless and can only survive under our conditions for nano-seconds. Allotropes (or isotopes if your English) are not different elements they are merely different compositions of elements, for example a car with a different size engine, looks the same but a bit different under the bonnet.
