Oganesson (Og)
Oganesson is element 118, a noble gas in group 18, period 7. A neutral atom has 118 protons, 177 neutrons and 118 electrons, 8 of them valence electrons. Many of its properties are predicted, because only a few atoms have ever been made.
Noble gas- Atomic number
- 118
- Atomic mass
- [295] u
- Valence electrons
- 8
- Protons · neutrons
- 118 · 177
- Electrons per shell
- 2, 8, 18, 32, 32, 18, 8
- At room temperature
- gas (expected)
Bohr model of oganesson
The Bohr model draws oganesson as a nucleus of 118 protons and 177 neutrons, with its 118 electrons on 7 circular shells: 2 in shell 1, 8 in shell 2, 18 in shell 3, 32 in shell 4, 32 in shell 5, 18 in shell 6, 8 in shell 7. Press Build the atom to watch the shells fill from the inside out. The outer ring (the Q shell) is dashed: the electrons there are the ones that take part in chemistry.
Real electrons don't travel in neat circles. They live in fuzzy orbitals, shown below, but the Bohr picture is the quickest way to count shells and valence electrons.
Electron configuration of oganesson
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p⁶
Short form (noble gas notation): [Rn] 7s² 5f¹⁴ 6d¹⁰ 7p⁶. The [Rn] stands for the electrons of radon, the noble gas before it.
This configuration is predicted from calculations; it has not been measured.
How many valence electrons does oganesson have?
Oganesson has 8 valence electrons.
Oganesson is in group 18, and for groups 13–18 you subtract 10 from the group number: 18 − 10 = 8. A full outer shell of eight makes it a noble gas that rarely reacts.
Protons, neutrons and electrons
| Protons | 118 | equal to the atomic number |
|---|---|---|
| Electrons | 118 | equal to the protons in a neutral atom |
| Neutrons | 177 | mass number 295 − 118 protons (for its longest-lived isotope, Og-295) |
Atoms of the same element can have different numbers of neutrons (isotopes). The count above uses the rounded atomic mass, the way it's taught in class.
Oganesson properties
| Symbol | Og |
|---|---|
| Category | Noble gas |
| Group · period · block | 18 · 7 · p |
| Atomic mass | [295] u |
| State at 25 °C | gas (expected) |
| Melting point | — |
| Boiling point | — |
| Density | — |
| Electronegativity (Pauling) | — |
| Atomic radius | — |
| First ionization energy | — |
| Electron affinity | — |
| Oxidation states | +6, +4, +2, +1, 0, −1 |
| Common ion charge | 0 |
| Discovered | 2006 by Joint Institute for Nuclear Research |
Where oganesson sits on the periodic table
Group 18: Helium, Neon, Argon, Krypton, Xenon, Radon.
Questions about oganesson
How many valence electrons does oganesson have?
Oganesson has 8 valence electrons.
How many protons, neutrons and electrons does oganesson have?
A neutral oganesson atom has 118 protons and 118 electrons. Its most common form has about 177 neutrons (mass number 295 − 118 protons).
What is the electron configuration of oganesson?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p⁶, written in short form as [Rn] 7s² 5f¹⁴ 6d¹⁰ 7p⁶. This configuration is predicted, not measured.
What does the Bohr model of oganesson look like?
A nucleus of 118 protons and 177 neutrons, circled by 7 electron shells holding 2, 8, 18, 32, 32, 18, 8 electrons.
What is the atomic number of oganesson?
118. The atomic number is the number of protons in the nucleus, and it is what makes an atom oganesson.