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ELI5 Yahaaa

The metal that will not change

Why Is Gold So Special?

Almost every metal dulls, rusts or tarnishes. Gold sits there looking exactly the same for thousands of years.

Iron Rusts away in a few wetyearsGold Unchanged after threethousand
Everything else gives in. Gold does not.
  1. Step 1 of 5

    It refuses to react.

    1 Air and watertouch it2 Its electronswill not joinin3 So nothing atall happens

    Rust and tarnish happen when a metal joins up with the oxygen in air. Gold's outer electrons are held so tightly that oxygen cannot get a grip — so a gold mask from a tomb comes out bright.

  2. Step 2 of 5

    It is astonishingly soft.

    A gram of golda small pinchDrawn into wireover 200 m long

    Pure gold can be hammered so thin you can see through it, and a single gram can be drawn into a wire longer than two football pitches. Jewellery is mixed with other metals just to make it tough enough to wear.

  3. Step 3 of 5

    It was made in exploding stars.

    1 Dying starscollide2 Gold atoms areforged in theblast3 The debrislater forms theEarth

    The Earth never made any gold. Every atom of it was forged in violent events far out in space — collapsing stars and colliding dead ones — long before the Earth formed out of that debris.

  4. Step 4 of 5

    Nearly all of it is still around.

    Mined once, long ago Melted andreshaped Melted and reshaped again Still in usetoday

    Because gold never corrodes and is too valuable to throw away, almost every gram ever mined still exists. Some of the gold in a modern ring was probably worn by somebody in the ancient world.

  5. Step 5 of 5

    It is genuinely rare.

    All the gold ever mineda cube about 22m each wayAll the iron minedfar, far morethan that

    All the gold ever mined would fit into a cube about twenty-two metres on a side. That scarcity, plus the refusal to tarnish, is why so many cultures independently settled on it as treasure.

    Gold is also a superb conductor that never corrodes, which is why the contacts inside good electronics have a thin gold plating.

The short version

Gold is treasured because it never corrodes, bends easily, and is rare — and every atom of it came from space.

Try it yourself

Compare an old copper coin with a gold-coloured one. The dull one has reacted with the air; gold never would.

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