TennessineElectron Configuration, Bohr Model, Valence Electrons & Orbital Diagram

The electron configuration of Tennessine is written as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d¹⁰ 7s² 7p⁵. Applying the Aufbau principle — filling orbitals from lowest to highest energy — plus the Pauli Exclusion Principle and Hund's Rule, we systematically place all 117 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d¹⁰ 7s² 7p⁵. The p-subshell adds three dumbbell-shaped orbitals (p_x, p_y, p_z) that collectively hold up to 6 electrons. In Tennessine, these outermost p-orbitals are the seat of its chemical personality — nearly complete and hungry for one more electron.

Tennessine follows the standard Aufbau filling order without exception. The noble gas shorthand [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁵ replaces the inner-shell electrons with the symbol of the preceding noble gas, highlighting that only the outer electrons — 5f¹⁴ 6d¹⁰ 7s² 7p⁵ — are chemically active. Note: for Period 4+ elements, the 4s orbital fills before 3d per Madelung's rule, even though 3d ends at a lower energy in the final atom.

Shell-by-shell, Tennessine's 117 electrons are distributed as: K-shell (n=1): 2 electrons; L-shell (n=2): 8 electrons; M-shell (n=3): 18 electrons; N-shell (n=4): 32 electrons; O-shell (n=5): 32 electrons; P-shell (n=6): 18 electrons; Q-shell (n=7): 7 electrons. The Q-shell (n=7) is the valence shell, containing 7 electrons.

Chemically, this configuration places Tennessine in Group 17 with oxidation states of 5, 3, 1, -1. This configuration directly predicts Tennessine's bonding mode, reactivity toward oxidizing and reducing agents, and the stoichiometry of its most common compounds.

The SPDF orbital model describes Tennessine's electrons not as planetary orbits but as three-dimensional probability clouds — each orbital a region of space where an electron is most likely to be found. Tennessine's 117 electrons occupy 19 distinct subshells: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁶ 5f¹⁴ 6d¹⁰ 7s² 7p⁵, governed by three quantum mechanical rules.

The Pauli Exclusion Principle ensures no two electrons in Tennessine share the same four quantum numbers (n, l, m_l, m_s). This is why the 1s orbital holds only 2 electrons, the full p-subshell holds 6, d holds 10, and f holds 14. Without this rule, all 117 electrons would collapse into the 1s orbital. Hund's Rule of Maximum Multiplicity is critical in Tennessine's p-subshell: the three p-orbitals (p_x, p_y, p_z) must each receive one electron before any pairing occurs. This minimizes electron-electron repulsion and explains Tennessine's 4 paired and -1 empty p-orbitals.

Following standard orbital filling, Tennessine fills orbitals in the sequence: 1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p → 5s → 4d → 5p → 6s → 4f → 5d → 6p → 7s → 5f → 6d → 7p. The final electron enters the 7p⁵ subshell, making Tennessine a p-block element with 7 valence electrons in Group 17.

The outermost electrons — 7p⁵ — are Tennessine's chemical agents. Seven valence electrons leave one np orbital with a vacancy. This empty slot has immense electron affinity (0 eV), driving Tennessine to react with extraordinary speed and force.

Tennessine's chemical reactivity is shaped by three interlocking properties: electronegativity, first ionization energy, and electron affinity (0 eV). Its electronegativity is not measurable (noble gas — no electronegativity scale applies).

Tennessine's ionization energy pattern reflects its block and period positioning, consistent with the expected periodic trend for Halogen elements.

Tennessine ranks among the most reactive nonmetals. Its vigorous oxidizing behavior — oxidizing metals, hydrogen, and other nonmetals — is driven by the extreme stability gained on completing its outer octet.

Placing Tennessine between Livermorium (Z=116) and Oganesson (Z=118) reveals the incremental property changes that make the periodic table a predictive tool.

Livermorium → Tennessine: adding one proton and one electron increases nuclear charge by 1. Valence electrons shift from 6 to 7 (Group 16 → Group 17). . Atomic radius decreases from 150 pm to 138 pm, consistent with increasing nuclear pull across a period.

Tennessine → Oganesson: the additional proton and electron in Oganesson changes the valence electron count from 7 to 8, crossing from Group 17 to Group 18. This boundary also marks a categorical transition from Halogen to Noble Gas. These comparisons confirm that Tennessine sits at a well-defined chemical inflection point in the periodic table.