Linked from

The 174 pages that link to Atomic number, each with the reason it gives.

• PotassiumNarrower topic: Potassium’s 19 protons define it as element 19.

• SodiumNarrower topic: Sodium’s atomic number, 11, identifies its nucleus and fixes its place in the periodic table.

• OganessonNarrower topic: Oganesson is element 118 because its nucleus contains 118 protons.

• Superheavy element synthesisNarrower topic: Superheavy elements are defined by their exceptionally high proton counts.

• HeliumNarrower topic: Helium’s atomic number is two because every helium nucleus contains two protons.

• BoronNarrower topic: Boron’s five protons define its place in the periodic table.

• TinNarrower topic: Tin’s atomic number 50 fixes its identity and nuclear charge.

• BerylliumNarrower topic: Beryllium’s four protons define its place as element 4.

• Element discoveryNarrower topic: A new element is defined by a proton number not previously confirmed.

• Transuranium elementNarrower topic: The boundary is exact: transuranium elements have atomic numbers above 92.

• Transactinide elementNarrower topic: The boundary is defined directly: transactinides have atomic numbers above 103.

• TennessineNarrower topic: Tennessine is element 117 because its nuclei contain 117 protons.

• UnbiniliumNarrower topic: Element 120 would have 120 protons, fixing its place beyond oganesson.

• Henry MoseleyNarrower topic: Moseley’s measurements established this quantity as the true basis of element order.

• Systematic element nameNarrower topic: It supplies the digits that determine a systematic element name.

• FleroviumNarrower topic: Flerovium’s atomic number, 114, defines its identity as an element.

• Chemical element namingNarrower topic: Naming procedures use atomic numbers to identify elements and construct provisional names.

• CoperniciumNarrower topic: Copernicium's 112 protons distinguish it from every other element.

• TechnetiumNarrower topic: Technetium's 43 protons distinguish it from molybdenum and ruthenium.

• DarmstadtiumNarrower topic: Darmstadtium is element 110 because every nucleus of it contains 110 protons.

• SeaborgiumNarrower topic: Seaborgium’s 106 protons distinguish it from every other element.

• UnbiuniumNarrower topic: The number 121 specifies unbiunium’s place among the elements.

• ZirconiumNarrower topic: Forty protons define zirconium and determine its place among the elements.

• PromethiumNarrower topic: Promethium’s 61 protons distinguish it from every other element.

• RutherfordiumNarrower topic: Rutherfordium’s 104 protons define its elemental identity.

• Superheavy element researchNarrower topic: A new element is established by demonstrating a nucleus with a previously unobserved proton count.

• FermiumNarrower topic: Fermium has 100 protons, the defining feature that places it at element 100.

• Synthetic elementNarrower topic: Producing a new element requires creating a nucleus with a previously distinct proton count.

• UnbihexiumNarrower topic: Unbihexium’s proposed identity is defined by having 126 protons.

• LivermoriumNarrower topic: Livermorium's identity as element 116 is fixed by its 116 protons.

• PraseodymiumNarrower topic: Praseodymium’s atomic number, 59, fixes its identity and place in the periodic table.

• RoentgeniumNarrower topic: Roentgenium’s 111 protons distinguish it from every other element.

• UnbiquadiumNarrower topic: The number 124 in Unbiquadium’s designation is its defining nuclear property.

• UnpenthexiumNarrower topic: The number 156 specifies unpenthexium's defining nuclear charge.

• NobeliumNarrower topic: Nobelium’s 102 protons distinguish it from every other element.

• UnbipentiumNarrower topic: The number 125 specifies how many protons an Unbipentium nucleus would contain.

• UnbitriumNarrower topic: The number 123 in unbitrium’s designation is its defining identifier.

• UnhexoctiumNarrower topic: 168 specifies the proton count that defines the hypothetical element.

• UnhexpentiumNarrower topic: Unhexpentium's proposed identity is fixed by its 165 protons.

• UnpentuniumNarrower topic: The number 155 identifies the element that the systematic name denotes.

• UnquadquadiumNarrower topic: The number 144 in unquadquadium’s designation is its defining atomic number.

• UntrienniumNarrower topic: The value 139 fixes which element the systematic name designates.

• UntriniliumNarrower topic: Untrinilium’s proposed identity rests on having 130 protons.

• UnbibiumNarrower topic: The number 122 specifies the proton count that unbibium would have.

• UnbioctiumNarrower topic: The number 128 in Unbioctium’s designation specifies its proton count.

• UnbiseptiumNarrower topic: The value 127 identifies the hypothetical element called unbiseptium.

• UnhexquadiumNarrower topic: The value 164 determines which hypothetical element unhexquadium names.

• UnhexseptiumNarrower topic: The value 167 defines which hypothetical element Unhexseptium names.

• UnoctquadiumNarrower topic: The value 184 defines which hypothetical element unoctquadium would be.

• UnpentbiumNarrower topic: The number 125 defines which hypothetical element Unpentbium would be.