Copper
Copper was the first metallic element to be extracted from rock. Some types of rock contain minerals rich in copper. These minerals are known as copper ores. As early as 9000BCE, humans heated copper ores with carbon to extract pure copper metal. Being metallic, copper is shiny and malleable (it can be hammered into sheets). This made copper perfect for making decorative plates, jewellery and utensils.
However, a truly revolutionary step in human civilization came when it was realized that copper could be mixed with the element tin to form the alloy bronze. Bronze was much stronger and harder than copper, and so it could be used to produce better tools. This discovery took human civilization out of the Stone Age and into the Bronze Age. Bronze could be used to make better weapons and Armour. This gave civilizations who used bronze a huge advantage over their rivals.
Copper is still a very important element because it is good at conducting electricity and is cheaper than other good conductors. This is why copper is used frequently in electrical wiring and the entire Australian telephone network.
Iron
Iron is much more difficult to extract and work with than copper because iron requires much higher temperatures. For this reason, the technology for extracting iron did ot appear until about 3000BCE.
Pure iron is not particularly useful because it is relatively soft and rusts easily. However, when iron is mixed with small amounts of carbon if it forms steel alloys that are harder, stronger and less likely to rust.
Steel changed many aspects of human civilization. Because steel is strong, it was used to make better utensils, tools, weapons and Armour. This made domestic life, agriculture and warfare easier. The use of steel tools defined the Iron Age, which went from approximately 1200BCE to 500 CE.
Oxygen
All living things on oxygen to survive, making this element possibly the most important of all. However, the discovery of oxygen also led to revolution in our understanding of how things burn.
Being a colorless, odorless gas, oxygen was much harder to identify than most solid elements. For this reason, oxygen gas was not discovered until 1772. This is when Swedish chemist Carl Whilhem Scheele (1742-1786) formed pure oxygen by heating mercury oxide with other compounds. Oxygen may also have been discovered at around the same time by British Scientist Joseph Priestley (1733-1804) and French chemist Antoine Lavoisier (1743-1794).
Uranium
The element uranium was first extracted in 1789 by German chemist Martin Heinrich Klaproth (1743-1817). However, until the early 1930s, uranium was considered a fairly useless material. It was then discovered that uranium could be used to create nuclear explosions. The extreme power of uranium was demonstrated with devastating effect in World War 2.
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The huge amount of energy stored in nuclear materials like uranium has also been used to help society. For example, it can be used to generate electricity in nuclear power plants. Nuclear power plants release much less carbon dioxide than traditional coal-fired power plants and now supply almost 15% of the world’s electricity. However, nuclear power plats produce dangerous nuclear waste, and the mining of uranium is damaging to the environment.
Silicon
Silicon forms the basis of most computer chips and without it the modern multi-billion-dollar industry that drives computing and electronics would not exist.
Silicon is unusual in that it is a semiconductor. This means that it can be made to conduct electricity like a metal, or insulate like a non-metal. Scientists discovered how to use this property to make a transistor-an early version of the silicon microchip. Before transistors, computers used vacuum tubes. The vacuum tubes were very large and very slow. This meant that computers processed information slowly, and they were so big that they would fill an entire room. The invention of the silicon transistor meant computers could process information much more quickly and could be made much smaller. This led to the invection of desktop computers, laptops, tablets and small phones.
Polymers
The term polymer does not refer to just one compound. It includes a wide range of compounds that make up important range of compounds that make up important materials such as rubber, plastic, glue, putty and synthetic fibers like polyester and nylon.
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One of the benefits of plastics and other polymers is that they trend to be extremely weather resistant and are unaffected by things like bacteria and mold. However, these properties have also led to environmental issues. Most plastics are not biodegradable, so they don’t rot when discarded into landfill. Instead, they will remain for centuries. Scientists are continuing research into polymers to find solutions to these environmental problems. One solution has been to create recyclable plastics and biodegradable plastic for use in packaging and shopping bags.
DNA
DNA (Deoxyribonucleic acid) is a molecular found in the nuclei of your cells. DNA contains all the genetic information that makes you who are you. Although DNA has existed as long as organisms have on Earth, its existence and structure have only been known since the mid-twentieth century.
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