As of 2025, there are 118 confirmed chemical elements officially recognized by IUPAC (International Union of Pure and Applied Chemistry). These range from Hydrogen (atomic number 1) to Oganesson (atomic number 118). Elements 119 and beyond have been attempted in laboratories but none have been confirmed yet.

The letter C starts the most element symbols, with 12 elements: Carbon (C), Calcium (Ca), Cadmium (Cd), Cerium (Ce), Californium (Cf), Chlorine (Cl), Curium (Cm), Copernicium (Cn), Cobalt (Co), Chromium (Cr), Cesium (Cs), and Copper (Cu). The letter S follows with 10 elements.

No. There are currently no element symbols that begin with the letter J or Q. All 118 element symbols use only 24 of the 26 English letters. The letters J and Q are the only ones missing from the periodic table's symbol list.

Many element symbols are derived from their Latin or Greek names. For example, Sodium is Na (from Latin natrium), Potassium is K (from Latin kalium), Iron is Fe (from Latin ferrum), Gold is Au (from Latin aurum), and Lead is Pb (from Latin plumbum). This historical naming convention preserves scientific continuity.

The most recently named elements are Nihonium (Nh, 113), Moscovium (Mc, 115), Tennessine (Ts, 117), and Oganesson (Og, 118), all officially named by IUPAC in November 2016. They completed the 7th period of the periodic table.

Element symbols are assigned by IUPAC. The symbol must be 1 or 2 letters, with the first letter capitalized and the second (if any) lowercase. Typically, the symbol is derived from the element's English name (e.g., Hydrogen → H, Helium → He), but may also come from its Latin, Greek, or historical name. For newly discovered elements, the discoverers propose a name and symbol which IUPAC must approve.

Elements are classified into 10 categories based on their chemical and physical properties: Alkali Metals (Group 1), Alkaline Earth Metals (Group 2), Transition Metals (Groups 3–12), Post-Transition Metals, Metalloids, Nonmetals, Halogens (Group 17), Noble Gases (Group 18), Lanthanides (rare earth metals), and Actinides (mostly radioactive).