Chemical substance can be transmuted into another element through a nuclear reaction. This is so, because all of the atoms in a sample of an element have the same number of protons, though they may be different isotopes, with differing numbers of neutrons. As of 2012, there are 118 known elements, about 80 of which are stable – that is, they do not change by radioactive decay into other elements. Some elements can occur as more than a single chemical substance (allotropes). For instance, oxygen exists as both diatomic oxygen (O) and ozone (O). The majority of elements are classified as metals.
There's More Than One of Everything the 16th best television episode of 2009, explaining "J.J. Abrams and company know all about big reveals... but this one, in which William Bell reveals himself as living in a parallel universe where the Twin Towers weren't lost, was one of their most indelible". In a comparison of "There's More Than One of Everything" and "The X-Files" episode "4-D", UGO Networks columnist Alex Zalben wrote that the "Fringe" episode won "by a landslide. This episode kicked the show into high gear, while '4-D' was "The X-Files" winding down." Jeff Jensen of "Entertainment Weekly" named "There's More Than One of Everything"