Period 7 element

A chemical element in the seventh row of the periodic table. The row runs from francium to oganesson and includes both naturally occurring and synthetic elements.

Periodic table: A tabular arrangement of chemical elements ordered by atomic number and recurring chemical properties. Period 7 is the table’s seventh horizontal row.
Aufbau principle: A model for electron configurations in which electrons occupy lower-energy orbitals before higher-energy ones. It gives a first-pass account of orbital filling across period 7.
Francium: A highly radioactive alkali metal with atomic number 87. It begins period 7 and has no stable isotopes.
Glenn T. Seaborg: An American nuclear chemist who co-discovered several transuranium elements and proposed the actinide series. His actinide concept reshaped how period 7 elements are displayed.
Extended periodic table: A proposed continuation of the periodic table beyond the currently confirmed elements. Predictions for periods beyond 7 depend on how orbital filling proceeds in extreme atoms.
Period (periodic table): A horizontal row of elements in the periodic table, whose atoms have the same number of occupied electron shells. The elements in this concept share the table’s seventh period.
Relativistic effect: A change in atomic structure or chemical behavior caused by relativistic motion of electrons near heavy nuclei. Relativistic effects alter orbital energies in the heaviest period 7 atoms.
Uranium: A naturally occurring radioactive actinide with atomic number 92. It is a familiar period 7 element used in nuclear energy and weapons.
Darmstadt heavy-ion research: A program at GSI in Darmstadt that produced and identified several superheavy elements. GSI teams discovered multiple elements in period 7’s later portion.
Chemical element 119: A proposed element with atomic number 119, not yet confirmed. Its synthesis would begin period 8 and test predictions from period 7.

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Period 6 elementCompared with: The next row contains actinides and substantially more radioactive elements.