Island of stability
Magic number (physics)In nuclear physics, a magic number is a number of nucleons (either protons or neutrons, separately) such that they are arranged into complete shells within the atomic nucleus. As a result, atomic nuclei with a "magic" number of protons or neutrons are much more stable than other nuclei. The seven magic numbers are 2, 8, 20, 28, 50, 82, and 126.
Chemical elementChemical substance not composed of simpler onesThe chemical elements ordered in the periodic table, as shown in the 32-column formatA chemical element is a species of atom defined by its number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its nucleus.Atomic numberThe atomic number or nuclear charge number (symbol Z, from the German Zahl, "number") 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 found in the nucleus of every atom of that element. The natural elements have atomic numbers from 1 for hydrogen to 92 for uranium.
UnbiuniumTheoretical chemical element with atomic number 121 (Ubu)—↑Ubu↓—unbinilium ← unbiunium → unbibium
Relativistic quantum chemistryRelativistic quantum chemistry combines relativistic mechanics with quantum chemistry to calculate elemental properties and structure, especially for the heavier elements of the periodic table. A prominent example is an explanation for the color of gold: due to relativistic effects, it is not silvery like most other metals. The term "relativistic effects" was developed in light of the history of quantum mechanics.
Systematic element nameA systematic element name is the temporary name assigned to an unknown or recently synthesized chemical element. A systematic symbol is also derived from this name. In chemistry, a transuranic element receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, such as the Transfermium Wars, controversies over the formal name and symbol have been protracted and highly political.
ThoriumChemical element with atomic number 90 (Th)Ce↑Th↓—actinium ← thorium → protactinium
Period (periodic table)A period on the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor. Arranged this way, elements in the same group (column) have similar chemical and physical properties, reflecting the periodic law.
Periodic tableTabular arrangement of the chemical elementsPeriodic table of the chemical elements showing the most or more commonly named sets of elements (in periodic tables), and a traditional dividing line between metals and nonmetals.
Extended periodic tableAn extended periodic table theorizes about chemical elements beyond those currently known and proven. The element with the highest atomic number known is oganesson (Z = 118), which completes the seventh period (row) in the periodic table. All elements in the eighth period and beyond thus remain purely hypothetical.
CeriumChemical element with atomic number 58 (Ce)–↑Ce↓Thlanthanum ← cerium → praseodymium
Magic number (physics)In nuclear physics, a magic number is a number of nucleons (either protons or neutrons, separately) such that they are arranged into complete shells within the atomic nucleus. As a result, atomic nuclei with a "magic" number of protons or neutrons are much more stable than other nuclei. The seven magic numbers are 2, 8, 20, 28, 50, 82, and 126.Chemical elementChemical substance not composed of simpler onesThe chemical elements ordered in the periodic table, as shown in the 32-column formatA chemical element is a species of atom defined by its number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its nucleus.Atomic numberThe atomic number or nuclear charge number (symbol Z, from the German Zahl, "number") 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 found in the nucleus of every atom of that element. The natural elements have atomic numbers from 1 for hydrogen to 92 for uranium.UnbiuniumTheoretical chemical element with atomic number 121 (Ubu)—↑Ubu↓—unbinilium ← unbiunium → unbibiumRelativistic quantum chemistryRelativistic quantum chemistry combines relativistic mechanics with quantum chemistry to calculate elemental properties and structure, especially for the heavier elements of the periodic table. A prominent example is an explanation for the color of gold: due to relativistic effects, it is not silvery like most other metals. The term "relativistic effects" was developed in light of the history of quantum mechanics.Systematic element nameA systematic element name is the temporary name assigned to an unknown or recently synthesized chemical element. A systematic symbol is also derived from this name. In chemistry, a transuranic element receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, such as the Transfermium Wars, controversies over the formal name and symbol have been protracted and highly political.ThoriumChemical element with atomic number 90 (Th)Ce↑Th↓—actinium ← thorium → protactiniumPeriod (periodic table)A period on the periodic table is a row of chemical elements. All elements in a row have the same number of electron shells. Each next element in a period has one more proton and is less metallic than its predecessor. Arranged this way, elements in the same group (column) have similar chemical and physical properties, reflecting the periodic law.Periodic tableTabular arrangement of the chemical elementsPeriodic table of the chemical elements showing the most or more commonly named sets of elements (in periodic tables), and a traditional dividing line between metals and nonmetals.Extended periodic tableAn extended periodic table theorizes about chemical elements beyond those currently known and proven. The element with the highest atomic number known is oganesson (Z = 118), which completes the seventh period (row) in the periodic table. All elements in the eighth period and beyond thus remain purely hypothetical.CeriumChemical element with atomic number 58 (Ce)–↑Ce↓Thlanthanum ← cerium → praseodymium*As an Amazon Associate I earn from qualifying purchases.