010Noble gas · Group 18 · Period 2
Neon
Neon (Ne) is element 10, a noble gas in the p-block — group 18, period 2. It is a gas at room temperature with 2 electron shells (2, 8) and an atomic mass of 20.17976 u.
- Atomic mass
- 20.18 u
- Phase · STP
- gas
- Melting
- 25 K · -249 °C
- Boiling
- 27 K · -246 °C
- Electronegativity
- —
- Density
- 0.9002 g/cm³
Photograph — Jurii, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons, source: https://images-of-elements.com/neon.php
Emission spectrum
The visible light Neon emits when energised — its unique spectral fingerprint.
Identity
- Atomic number
- 10
- Standard atomic weight
- 20.18 u
- Category
- Noble gas
- Group
- 18 · Noble gases
- Period
- 2
- Block
- p-block
- Oxidation states
- 0
Physical properties
- Melting point
- 25 K · -249 °C
- Boiling point
- 27 K · -246 °C
- Density
- 0.9002 g/cm³
- Molar heat capacity
- —
- Atomic radius
- 154 pm
- Electron affinity
- -116 kJ/mol
Atomic structure
10protons
10neutrons
10electrons
8valence e⁻
- Noble-gas notation
- [He] 2s2 2p6
- Full configuration
- 1s2 2s2 2p6
- Electrons per shell
- 2, 8
Periodic trends
Where Neon ranks across all 118 elements.
Ionization energies
Energy to remove each successive electron (kJ/mol).
2.1k1
4.0k2
6.1k3
9.4k4
12.2k5
15.2k6
20.0k7
23.1k8
115.4k9
131.4k10
Successive ionization energies (kJ/mol, log scale).
Discovery
- Discovered
- 1898
- Discovered by
- Morris Travers
- Named by
- —
- Appearance
- colorless gas exhibiting an orange-red glow when placed in a high voltage electric field