Linked from

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

• Periodic tableRelated: Increasing atomic number sets the table's ordering principle.

• IsotopeRelated: Isotopes of one element all have the same atomic number.

• Chemical elementRelated: It is the defining count that distinguishes one element from every other.

• ProtonRelated: Changing the proton count changes an atom into a different element.

• ChlorineRelated: Chlorine’s 17 protons define it as element 17.

• Atomic nucleusRelated: Proton count gives the nucleus its identity as a particular element.

• CalciumRelated: Calcium’s atomic number, 20, defines its elemental identity.

• IonRelated: Ion formation changes electron count, not the atomic number.

• Alkali metalRelated: Atomic number distinguishes the successive elements in the alkali-metal group.

• Ionization energyRelated: It sets nuclear charge and helps explain periodic changes in electron binding.

• Dmitri MendeleevRelated: Ordering by atomic number later explained periodicity more accurately than Mendeleev's atomic-weight ordering.

• IodineRelated: Iodine’s atomic number, 53, fixes its identity and nuclear charge.

• Periodic trendsRelated: Increasing atomic number across a period adds nuclear charge one proton at a time.

• X-ray fluorescenceRelated: Element identity determines the energies of its characteristic X-ray lines.

• ZincRelated: Zinc’s atomic number is 30.

• ActinideRelated: The series runs through consecutive atomic numbers, from actinium's 89 to lawrencium's 103.

• GoldRelated: Gold’s atomic number, 79, fixes its identity regardless of isotope or charge.

• Uranium-238Related: Its 92 protons identify uranium regardless of neutron count.

• NihoniumRelated: Nihonium is element 113 because its nuclei contain 113 protons.

• Nuclear transmutationRelated: A change in proton count is the defining criterion for transmutation.

• Potassium ionRelated: Potassium’s atomic number is 19, fixing the identity of its ion.

• Mass numberRelated: Together with mass number, it specifies a nuclide’s neutron count.

• NuclideRelated: Nuclides with the same atomic number belong to the same element.

• Periodic lawRelated: Ordering elements by proton count gives the modern periodic law its organizing variable.

• Sodium ionRelated: Sodium’s 11 protons determine its identity even after it becomes an ion.

• AtomRelated: It gives each element its defining identity.

• Chemical symbolRelated: A symbol identifies an element whose defining property is its atomic number.

• UnunenniumRelated: The defining identity of ununennium is 119 protons.

• AnionRelated: Gaining electrons changes charge, not the atomic number or element.

• Effective nuclear chargeRelated: It sets the unscreened nuclear charge from which effective charge is estimated.

• Relativistic effectRelated: Larger nuclear charge draws inner electrons faster, making relativistic effects stronger in heavy atoms.

• Cahn–Ingold–Prelog priority rulesRelated: The first point of comparison when attached atoms differ.

• E–Z notationRelated: When directly attached atoms differ, the higher atomic number gives the higher substituent priority.

• Rutherford scatteringRelated: The scattering strength depends on the target nucleus’s positive charge, indexed by atomic number.

• IsobarRelated: Isobars differ in this number.

• MoscoviumRelated: Moscovium is element 115 because each of its nuclei contains 115 protons.

• Rutherford modelRelated: Nuclear charge in the model corresponds to the positive charge later identified with proton number.

• YttriumRelated: Yttrium’s atomic number, 39, determines its position in the periodic table.

• BariumRelated: Barium’s 56 protons distinguish it from every other element.

• Calcium ionRelated: Calcium’s atomic number remains 20 after it becomes an ion.

• XenonRelated: Xenon’s 54 protons distinguish it from every other element.

• Calcium-48Related: Its 20 protons give calcium-48 the atomic number of calcium.

• Isotopic abundanceRelated: Isotopes share this number while differing in neutron count.

• LanthanumRelated: Lanthanum's 57 protons distinguish it from every other element.

• RubidiumRelated: Rubidium’s 37 protons distinguish it from every other element.

• ArgonRelated: Argon’s atomic number of 18 means each argon nucleus contains 18 protons.

• MolybdenumRelated: The value 42 distinguishes molybdenum from every other element.

• Moseley's lawRelated: It is the element-specific quantity related to X-ray frequency.

• ScandiumRelated: Scandium’s atomic number, 21, fixes its identity and place in the periodic table.

• TerbiumRelated: The value 65 distinguishes terbium from every other element.