9F18.99840316
Fluorine
Halogen
Gas at STP
Period 2Group 17Block PDiscovered 1670
[He]2s2 2p5
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.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 9 |
| Atomic Mass | 18.99840316 u |
| Electron Configuration | [He]2s2 2p5 |
| Oxidation States | -1 |
| Electronegativity | 3.98 (Pauling) |
| Atomic Radius | 135 pm |
| Ionization Energy | 17.423 eV |
| Electron Affinity | 3.339 eV |
| Block | P |
Physical Properties
| Standard State | Gas |
| Melting Point | 53.53 K (-219.6 °C) |
| Boiling Point | 85.03 K (-188.1 °C) |
| Density | 0.001696 g/L |
| CPK Color | #90E050 |
Classification
| Category | Halogen |
| Group Block | Halogen |
| Period | 2 |
| Group | 17 |
| Block | P |
Discovery
| Year Discovered | 1670 |
| Discovered By | André-Marie Ampère |
| Named By | Humphry Davy |
| Electron Shells | 2, 7 |