MediumScience
"I am the basis of all life on Earth. I can be as soft as pencil lead or as hard as the hardest substance known. I am in every living thing and every dead thing. What am I?"
Answer
Carbon
Explanation
Carbon is the chemical backbone of all organic life. In the form of graphite it is soft enough to mark paper. As diamond it is the hardest natural substance. Carbon is found in all living organisms and all formerly living things.
This is a medium riddle in the Science category — Riddles about physics, space, biology and the laws of the universe.
Tags:sciencechemistrynature
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