10Neon

Neon is a noble gase in group 18, period 2. At 25 °C it is a gas.

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

Symbol: Ne
Atomic number: 10 protons in the nucleus
Standard atomic weight: 20.180 ± 0.001
Electron configuration: [He] 2s² 2p⁶
Electrons in each shell: 2, 8
Group, period, block: 18, 2, p
Family: Noble gases
State at 25 °C: gas
Electronegativity: no value
First ionisation energy: 2080.7 kJ/mol (21.564541 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.