Planet Earth and every thing living on it is made up of elements. An element is a pure substance made up of atoms all of the same type. Some elements are vital to our survival, while others – depending on the dose – are harmful to us.
So where did elements come from? How are elements classified? What uses have we found for elements in our modern society? This context may be able to provide answers to these questions.
Where did elements come from?
Here’s what Martin Rees, UK’s Astronomer Royal, recently said:
And we know that every atom in our body was forged in an ancient star somewhere in the Milky Way. We are literally the ashes of long-dead stars – the nuclear waste from the fuel that makes stars shine. To understand ourselves, we must understand the atoms we’re made of – but we must also understand the stars that made those atoms.
The experiments that will be conducted at the Large Hadron Collider at CERN in Switzerland will allow scientists to better understand the fine structure of atoms and explore the conditions that are thought to have existed at the moment of creation of the universe.
Arranging the elements
The periodic table of elements is a very useful tool, and it can be used to organise many of the ideas in chemistry. The history of its development is a fascinating story, demonstrating the roles that imagination and creativity play in science.
Which elements are we humans made up of? Does our diet provide us with all the elements we need? What happens if we have too much or too little of a given element? This section provides answers to these intriguing questions.
Uses of metals
Of the 92 naturally occurring elements, 78 are metals. Our modern society is literally built with metals. But forget iron and aluminium – titanium is the metal of the future, with titanium alloys increasingly being used in transport, medical science and high-tech sports.
Isotopes, particularly those that are radioactive, are widely used in our modern society. Perhaps the best known of these is carbon-14, which is used to date artefacts of historical importance such as ancient moa bones found in an archaeological dig at the Wairau Bar close to the town of Blenheim.
- Nature of Science
Science knowledge is reliable and durable but never absolute or certain. This knowledge is subject to change. Scientific claims change as new evidence – made possible by advances in thinking and technology – is brought to bear on these claims.