52Tellurium

Tellurium is a metalloid in group 16, period 5. At 25 °C it is a solid.

Shells: 2, 8, 18, 18, 6. A simple picture: electrons do not move in circles.

Symbol: Te
Atomic number: 52 protons in the nucleus
Standard atomic weight: 127.60 ± 0.03Some geological samples have an unusual isotope mix, so their atomic weight can fall outside this range.
Electron configuration: [Kr] 4d¹⁰ 5s² 5p⁴
Electrons in each shell: 2, 8, 18, 18, 6
Group, period, block: 16, 5, p
Family: Metalloids
State at 25 °C: solid
Electronegativity: 2.1 (Pauling scale)
First ionisation energy: 869.3 kJ/mol (9.009808 eV)

Where these numbers come from

Atomic weight: IUPAC CIAAW, abridged standard atomic weights 2024. Electron configuration and ionisation energy: NIST Atomic Spectra Database. Family, state and electronegativity: PubChem. See Sources. Melting points, boiling points and densities are left out for now: published values differ between sources, and we will add them once each has been checked.