There are about 90 natural elements found on Earth, and across the Universe. Most are silvery-grey metals or colourless gases. They may look rather similar but the unique properties of each, and the compounds that they form with each other, are what produce the astonishing variety of materials and colours all around us. They are what make us too.
Explore the Elements gallery at the Ulster Museum to find out more about these building blocks of the Universe.
Elements of the Universe
Silicon carbide, a simple compound of silicon and carbon, is a widely used synthetic abrasive but it is also found as microscopic grains in some meteorites. The silicon carbide was created in giant red stars and scattered into Space by stellar winds. As our Solar System formed from a cloud of dust, these grains were swept up and incorporated into the first planets. Meteorites represent debris from the beginning of the Solar System, around 4567 million years ago, but the silicon carbide grains are even older still.
Elements of the Earth
Many minerals are named after the place where they were first found, and some elements are too. Strontium was first isolated in 1790 from the mineral strontianite, strontium carbonate. Both take their name from the Scottish village of Strontian, where the mineral was first found. The element was discovered by Adair Crawford and William Cruikshank, chemistry professors at the Royal Military Academy in Woolwich, but Adair was originally from near Belfast.
Elements of Life
Living things are dominated by just a few common elements - carbon, hydrogen, oxygen, nitrogen - but some of the most common elements are hardly found at all. Aluminium seems not to be used by any plants or animals while silicon, one of the most abundant rock-forming elements, is found in just a few, mostly microscopic, organisms. Among these are the beautiful ‘glass sponges’ which make their skeletons from silica (silicon dioxide).
Elements of Death
Hazardous substances have long been used to enhance beauty. In the 1700s it was fashionable for the aristocracy to whiten their faces using ceruse, a powdered form of the white lead mineral cerussite (lead carbonate). Lead is damaging to nerves, kidneys, skin and many other organs. Applying white lead to the face often caused ulcers, which needed more ceruse to cover them. The most famous ‘victim of cosmetics’ was Maria Gunning, Countess of Coventry, who died rom lead poisoning aged just 27.
Elements of Progress
Copper was the first metal to be smelted from mineral ores more than 5000 years ago. This led to a revolution in tool and weapon-making, the Bronze Age, that lasted for 2000 years, until the start of the Iron Age. Copper became important again around 500 years ago as a key ingredient, along with zinc, in brass. In the last 200 years copper’s electrical conductivity, second only to silver, has become increasingly vital for telecommunications and electric power.
Elements of Technology
Some elements are catalysts: they help chemical reactions without being used up themselves. Platinum, palladium and rhodium are among the rarest of elements yet more than half of total amount of these metals mined each year is used in catalytic convertors for motor vehicle exhausts. They transform toxic gases into non-toxic ones.Each catalytic converter contains just two grams of these elements, but this is spread across more than 200 square metres of corrugated iron-chromium-aluminium alloy foil.
Elements of Colour
Cubic zirconia is a synthetic gemstone made from zirconium oxide. A small amount of yttrium is added to ensure that it forms stable cubic crystals, like diamond. Adding tiny amounts of certain other elements – such as chromium, neodymium, holmium or erbium - can produce a diverse range of colours in what is otherwise a brilliantly sparkling, but colourless, gemstone.
Elements of Light
Electronic flashbulbs produce a brilliant burst of light - but only once since the electric current ignites a fine zirconium metal wire inside the bulb. The best quality bulbs have contacts made of rhenium, a metal with one of the highest melting points of an element, to withstand the very high electric current needed to fire these bulbs.
Elements of Wealth
Gold and silver were the metals of choice for the first coins, more than 2500 years ago, and they continued to be used for many coins until about 200 years ago. Since then cheaper metals and alloys, such as copper, zinc, nickel and even steel, have been increasingly used. Aluminium too because it is so cheap, but this was not always the case. Until 1886 the metal was so difficult to produce that it was more valuable even than gold!
Elements of Fashion
Gold is rare and expensive, affordable only to the wealthy. Brass is cheap and, some might say, vulgar when used in fashion items. But metallurgists have produced particular alloys of brass that look a lot like gold. Prince’s Metal, named after Prince Rupert of the Rhine, is a yellow-coloured alloy of 75% copper and 25% zinc while Pinchbeck Brass, with about 90% copper and 10% zinc looks even more like gold.
Elements of Fission
Radium, mixed with zinc sulfide, was painted onto clock and watch faces throughout the first half of the 20th Century. Radiation causes the zinc sulfide to glow but, although radium itself has a half-life of more than 1600 years, these dials stop glowing after just a few decades because this same radiation damages the crystal structure of the zinc sulfide.