9F18.998
Diatomic Non-Metalp-block
Fluorine
Element 9 on the periodic table, symbol F, group 17, period 2.
Fluorine is a chemical element with symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.
Properties
- Atomic Number
- 9
- Atomic Mass
- 18.9984 u
- Group
- 17
- Period
- 2
- Block
- p-block
- Category
- Diatomic Non-Metal
- State at 25 °C
- Gas
- Melting Point
- 53.5 K · -219.7 °C
- Boiling Point
- 85 K · -188.1 °C
- Density
- 1.696 g/L
- Atomic Radius
- 50 pm
- Electronegativity
- 3.98
- Oxidation States
- -1
- Abundance in Crust
- 585 mg/kg
- Discovered
- 1886
- Discovered By
- André-Marie Ampère
Electron Configuration
[He] 2s2 2p5
1s2 2s2 2p5
Ionisation Energies (kJ/mol)
- 1. 1,681
- 2. 3,374.2
- 3. 6,050.4
- 4. 8,407.7
- 5. 11,022.7
- 6. 15,164.1
- 7. 17,868
- 8. 92,038.1
Elements near Fluorine
Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.