Atomic number - Wikipedia
The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (np) or the number of protons …
List of chemical elements - Wikipedia
118 chemical elements have been identified and named officially by IUPAC. A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [1]
Atomic number - Simple English Wikipedia, the free encyclopedia
The atomic number (symbol: Z) of an atom is the number of protons in the nucleus of the atom. [ 1 ] [ 2 ] The atomic number of an atom identifies which element it is. In a neutral atom, the atomic number is equal to the number of electrons orbiting the nucleus. [ 1 ]
Element List – Element Names, Symbols, and Atomic Numbers
2014年5月17日 · Here is a list of elements of the periodic table, their atomic numbers, and element symbols. The list is ordered by increasing atomic number, which is the number of protons in an atom of that element.
Periodic table - Wikipedia
The above table shows the names and atomic numbers of the elements, and also their blocks, natural occurrences and standard atomic weights. For the short-lived elements without standard atomic weights, the mass number of the most stable known isotope is used instead.
What Is an Atomic Number? Definition and Examples
2020年10月6日 · Atomic Number vs Mass Number. The atomic number is the number of protons found in the nucleus of an atom, which uniquely identifies its element. The atomic number is also called the proton number. It is denoted by the symbol Z and is the subscript in atomic notation.
Atomic number | Definition & Facts | Britannica
2025年1月17日 · Atomic number, the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus. Accordingly, the number of protons, which is always equal to the number of electrons in a neutral atom, is also the atomic number.