Fluorine

Fluorine (F)

A poisonous pale yellow gaseous element belonging to group 17 of the periodic table (The halogens). It is the most chemically reactive and electronegative element. It is highly dangerous, causing severe chemical burns on contact with flesh. Fluorine was identified by Scheele in 1771 and first isolated by Moissan in 1886.
Atomic Number9
Atomic Weight18.998403163
Mass Number19
Group17
Period2
Blockp
Protons9 p+
Neutrons10 n0
Electrons9 e-
Liquid fluorine tighter crop.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
50 pm
Atomic Volume
Covalent Radius
64 pm
Metallic Radius
Ionic Radius
128.5 pm
Crystal Radius
114.5 pm
Van der Waals radius
147 pm
Density
0.001553 g/cm³
Boiling Point
85.01 K
Melting Point
53.53 K
Electrons per shell2, 7
Electronegativity
3.98
Electrophilicity
3.8658074231362 eV/particle
Proton Affinity
340.1 kJ/mol
Electron Affinity
3.4011897 eV/particle
Ionization Potential
17.42282 eV/particle
Heat of Vaporization
6.54 kJ/mol
Heat of Fusion
0.51 kJ/mol
Heat of Formation
79.335 kJ/mol
Molar Heat Capacity
31.304 J/(mol K)
Specific Heat Capacity
0.824 J/(g⋅K)
Thermal Conductivity
0.028 W/(m K)
Gas Basicity
315.1 kJ/mol
Dipole Polarizability
3.74 a₀
C6 Dispersion Coefficient
9.52 a₀
Oxidation States-1
Color
Colorless
Crystal StructureBase Centered Monoclinic (MCL)
Lattice Constant
Bulk Modulus
Electrical Resistivity
Electron Configuration[He] 2s2 2p5
Magnetic Ordering
Magnetic Susceptibility
PhaseGas
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryHalogens, Halogens
CAS GroupVIIB
IUPAC GroupVIIA
Glawe Number102
Mendeleev Number106
Pettifor Number102
Geochemical Classsemi-volatile
Goldschmidt Classlitophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
585 mg/kg
Abundance in Oceans
1.3 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe0.00004%

Isotopes of Fluorine

Stable Isotopes
19F
Unstable Isotopes
14F 15F 16F 17F 18F 20F 21F 22F 23F 24F 25F 26F 27F 28F 29F 30F 31F

History

In 1529, Georigius Agricola described the use of fluorspar as a flux. In 1670 Heinrich Schwandhard found that glass was etched when exposed to fluorspar treated with acid. In 1810, French scientist Andre-Marie Ampere proposed that fluoric acid was a compound of hydrogen with a new element. The element was finally isolated in 1886 by Henri Moissan. From the Latin and French fluere, flow or flux

DiscoverersHenri Moissan
Discovery LocationFrance
Discovery Year1886
Name OriginLatin: fluere (flow).
Fluorine is highly toxic and corrosive
Fluorine reacts violently with water to produce oxygen

Uses

Compounds of fluorine, including sodium fluoride, are used in toothpaste and in drinking water to prevent dental cavities. Hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) now serve as replacements for CFC refrigerants. Fluorine and its compounds are used in processing nuclear fuel. Used in refrigerants and other fluorocarbons. Also in toothpaste as sodium fluoride (NaF) and stannous fluoride (SnF2); also in Teflon.

Sources

Found in the minerals fluorite (CaF2) and cryolite(Na3AlF6). Electrolysis of hydrofluoric acid (HF) or potassium acid fluoride (KHF2) is the only practical method of commercial production.