Next time to one of the universe's rarer chemicals and horribly toxic though it is, without it we'd be the proverbial particle short of a nucleus. Matt Wilkinson on the extraordinary virtues of element number 3, lithium. These are absorbed by the nuclei of lithium-6 which immediately disintegrates to form helium and hydrogen-3 which then go on to form other elements and as they do the bomb explodes with the force of millions of tonnes of TNT. This compound is capable of releasing massive amounts of energy from the neutrons released by the atomic bomb at its core.

The hydrogen of hydrogen bombs is actually the compound lithium hydride, in which the lithium is the lithium-6 isotope and the hydrogen is the hydrogen-2 isotope (deuterium). The Royal Society of Chemistry and Compound Interest are celebrating IYPT with these element graphics, which will be released throughout the year Source: © 2019 Andy Brunning/Royal Society of Chemistry This longevity has been extended to lithium batteries of the more common 1.5 volts variety (in which the cathode is iron disulfide) that are in everyday gadgets such as clocks, and lithium is now beginning to be used for rechargeable batteries. They function with lithium as the anode, iodine as the solid electrolyte, and manganese oxide as the cathode – and they have a lifespan of ten years. They are implanted to supply the electrical energy for heart pacemakers. Lithium batteries which operate at 3 volts or more are used in devices where compactness and lightness are all-important. It will even work well at temperatures as low as -60 o C and has been used for vehicles in the Antarctic. Lithium stearate, made by reacting stearic acid with lithium hydroxide, is an all-purpose high-temperature grease and most greases contain it. Magnesium-lithium alloy is used in protective armour plating and aluminium-lithium reduces the weight of aircraft thereby saving fuel. Lithium metal goes into alloys with magnesium and aluminium, and it improves their strength while making them lighter. Lithium oxide goes into glass and glass ceramics. Lithium is used commercially in various ways. Lubricating a bearing with lithium grease How it works is still not known for certain, but it appears to prevent overproduction of a chemical messenger in the brain. Other patients responded similarly and lithium therapy is now used all around the world to treat this mental condition. The man responded so well that within days he was transferred to a normal hospital ward and was soon back at work. Cade then gave his most mentally disturbed patient an injection of the same solution. He had injected guinea pigs with a 0.5% solution of lithium carbonate, and to his surprise these normally highly-strung animals became docile, and indeed were so calm that they would sit in the same position for several hours. Its calming effect on the brain was first noted in 1949, by an Australian doctor, John Cade, of the Victoria Department of Mental Hygiene. However, in small doses it is prescribed as a treatment for manic depression (now called bipolar disorder). Lithium is moderately toxic as discovered in the 1940s when patients were given lithium chloride as a salt substitute. Once lithium's discovery had been announced others soon found it to be present in all kinds of things such as grapes, seaweed, tobacco, vegetables, milk and blood. A sample of lithium metal was finally extracted in 1855 and then by the electrolysis of molten lithium chloride. However, unlike sodium, which Humphry Davy had isolated in 1807 by the electrolysis of sodium hydroxide, Arfwedson was unable to produce lithium by the same method. He reasoned that it was a new alkali metal and lighter than sodium. He deduced that petalite contained an unknown metal, which he called lithium from the Greek word for a stone, lithos, although he never actually produced any. The element was discovered on Earth in 1817 by Johan August Arfwedson (1792-1841) in Stockholm when he investigated petalite, one of the first lithium minerals to be discovered (it was observed to give an intense crimson flame when sprinkled on to a fire). Lithium is rare in the universe, although it was one of the three elements, along with hydrogen and helium, to be created in the big bang.

Lithium periodic table