Hydrogen (H)
One
of hydrogen's isotopes, tritium (3H) is radioactive. Tritium is
produced in nuclear reactors and is used in the production of the hydrogen
bomb. It is also used as a radioactive agent in making luminous paints and as a
tracer isotope.
- commercial fixation of nitrogen
from the air in the Haber ammonia process
- hydrogenation of fats and oils
- methanol production, in
hydrodealkylation, hydrocracking, and hydrodesulphurization
- rocket fuel
- welding
- production of hydrochloric acid
- reduction of metallic ores
- for filling balloons (hydrogen
gas much lighter than air; however it ignites easily)
- liquid H2 is
important in cryogenics and in the study of superconductivity since its
melting point is only just above absolute zero
Both lithium metal and its compounds have many uses.
- lithium stearate is mixed with
oils to make all-purpose and high-temperature lubricants
- lithium hydroxide is used to
absorb carbon dioxide in space vehicles
- lithium is alloyed with
aluminium, copper, manganese, and cadmium to make high perfomance alloys
for aircraft
- Bahnmetall consists of lead
containing 0.04% lithium, 0.7% calcium and 0.6% sodium is harder than pure
lead and was used for railroad car bearings in Germany.
- compounds such as LiAlH4
and organolithium reagents (LiMe, LiPh, etc.) are very important as
reagents in organic chemistry
- lithium metal has the highest
specific heat of any solid element and so heat transfer applications
- various nuclear applications
- lithium is sometimes used as
battery anode material (high electrochemical potential) and lithium
compounds are used in dry cells and storage batteries
- lithium is used in the
manufacture of special high strength glasses and ceramics
- sometimes, lithium-based
compounds such as lithium carbonate (Li2CO3) are
used as drugs to treat manic-depressive disorders.
- sodium metal is used in the
preparation of tetraethyl lead, PbEt4, an important anti-knock
reagent in leaded petrol (gasoline) - fortunately being phased out in many
countries because of lead pollution problems
- sodium metal is used in the
preparation of titanium metal from TiCl4
- the metal is used in the
manufacture of sodamide, sodium cyanide, sodium peroxide, and sodium
hydride
- the metal is used in the
reduction of organic esters, and in the preparation of organic compounds
- the alloy with potassium, NaK,
is an important heat transfer agent and a good chemical reducing agent (as
some proportions of Na and K are liquid at room temperature).
- sodium compounds including
"common salt" (sodium chloride, NaCl), "soda ash"
(sodium carbonate, Na2CO3), "baking soda"
(sodium bicarbonate, NaHCO3, "bicarb"), and
"caustic soda" (sodium hydroxide, NaOH), are important to the
paper, glass, soap, textile, petroleum, chemical, and metal industries
- sodium vapour is used in lamps
for street lighting
- table salt - don't use too
much!
- The superoxide KO2
is used in breathing apparatus where moisture in the breath and carbon
dioxide reacts with it to release oxygen [2KO2 + H2O
+ 2CO2 → 2KHCO3 + O2 ]
- the alloy of potassium with
sodium (NaK) is used as a heat-transfer medium in nuclear reactors. The
alloy is liquid at ambient temperature and is a good reducing agent in the
chemistry laboratory
- fertilizers - usually as the
chloride, sulphate, nitrate, or carbonate
- possium nitrate, KNO3,
and potassium chlorate, KClO3, are used in fireworks
- potassium bromide, KBr, was
used as an antaphrodisiac - oh dear!
- potassium permanganate, KMnO4,
is an important oxidizing agent
- low-sodium salt
- potassium hydroxide is used in
the preparation of potassium phosphates for liquid detergents
- rubidium is easily ionized, and
so has possible use in "ion engines" for space vehicles (but
caesium is somewhat more efficient)
- used as a "getter" in
vacuum tubes
- photocell component
- used for making special glasses
- RbAg4I5
has the highest room temperature conductivity of any known ionic crystal.
At ambient temperature, its conductivity is about the same as dilute
sulphuric acid, suggesting uses in thin film batteries
- the metal can be used in ion
propulsion systems. Although not usable in the earth's atmosphere, 1 kg of
caesium in outer space could propel a vehicle 140 times as far as the
burning of the same amount of any known liquid or solid. It is more
efficient than rubidium.
- used in atomic clocks
- because of its high oxygen
affinity, the metal is used as a "getter" in electron tubes
- used in photoelectric cells and
vacuum tubes
- IR lamps
- Francium has no uses.
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