F see Fluorine; Fe see Iron
Fermium (Fm)
Key facts…
Name: fermium
Symbol: Fm
Atomic number: 100
Atomic weight: 257
Position in Periodic Table: inner transition metal;
period 7 (actinide series)
State at room temperature: solid
Colour: unknown
Density of solid: n/a
Melting point: 1,527°C
Boiling point: n/a
Origin of name: named after the scientist Enrico
Fermi
Shell pattern of electrons: 2–8–18–32–30–8–2
Element 100. It is an artificial and
radioactive rare-earth element in the
actinide series in the Periodic Table.
Very little is known about fermium.
Discovery
Fermium was first discovered by
Albert Ghiorso and others in 1952
at Los Alamos, New Mexico and the
University of California at Berkeley in
the radioactive fallout from a nuclear
test in the Pacific Ocean.
Fluorine: Polytetrafluoroethene coatings are found on
many household pans to give them their non-stick finish.
The only problem with the material is that it is soft and
so can be scratched with metal implements. For this
reason, wooden or plastic implements need to be used
with non-stick pans.
Technology
Since so little has been isolated, it has
no uses.
Geology
It is not found in the environment.
Biology
It is not found in living things.
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Fluorine (F)
Key facts…
Element 9. Fluorine is the lightest halogen
in group 7 in the Periodic Table.
Fluorine, a pale-yellow, very corrosive
gas that is slightly heavier than air, is the
most reactive chemical element in
existence.
Fluorine combines with all other
elements except helium, neon and argon.
It is an extremely poisonous gas.
Name: fluorine
Symbol: F
Atomic number: 9
Atomic weight: 18.99
Position in Periodic Table: group 7 (17),
(halogens); period 2
State at room temperature: gas
Colour: pale-yellow
Density of gas at 20°C: 1.58 g/cc
Melting point: –219°C
Boiling point: –188°C
Origin of name: from the Latin word fluere,
meaning to flow
Shell pattern of electrons: 2–7
Discovery
Geology
French chemist Henri Moissan
discovered fluorine in 1886. Because it
is so reactive and difficult to isolate, he
eventually had to use an apparatus made
from platinum. His success gained him
the Nobel Prize for chemistry in 1906.
It is never found as a native element, but
mainly as the mineral fluorite, calcium
fluoride (CaF2), also known as fluorspar
and Bohemian emerald.
Biology
Fluorine is found in bones and teeth.
Adding fluoride to water has become
popular because it helps teeth resist decay.
Technology
It goes into many fluoride-containing
plastics. Hydrofluoric acid is used
for etching the glass of light bulbs.
Fluorochloro-hydrocarbons are
used in air conditioning and in
refrigeration. Fluorides are put
into water supplies to help prevent
tooth decay.
Fluorite is purple.
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For more on fluorine, see Volume 14: Chlorine,
Fluorine, Bromine and Iodine in the Elements set.