Chemical element

Last revised by Dr Daniel J Bell on 07 May 2022

There are now 118 confirmed chemical elements in the periodic table. A chemical element describes atoms which share the same specific number of protons in their nucleus (atomic number or Z). For example, all atoms of carbon, regardless of their number of electrons (determines ionization) or neutrons (determines isotope), have six nuclear protons, i.e. carbon has an atomic number of 6.

The elements with atomic numbers 1-94 (hydrogen to plutonium) are naturally-occurring. The remaining 24 elements have been synthesized in the laboratory, many in such tiny (atomic) quantities, with such short half-lives, that any further useful chemical investigation is precluded at this stage.

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Cases and figures

  • Figure 1: periodic table
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