Multiple choice general knowledge science & technology

The long hot squeeze If you were to take a lump of coal and squeeze for a long time at very high temperatures, you would end up with:

  1. Graphite

  2. Volcanic glass, also known as obsidian

  3. A smaller lump of coal

  4. A diamond
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When coal (which is composed mostly of carbon) is subjected to extreme pressure and temperature deep within the Earth over millions of years, the carbon atoms rearrange into a crystalline structure to form diamonds. This process requires pressures of 45-60 kilobars and temperatures of 900-1300°C. The other options are incorrect transformations of coal.

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