EasyScience
"I am invisible yet without me nothing burns and nothing lives. I make up a fifth of the air around you. Too much of me is toxic, too little and you die. What am I?"
Answer
Oxygen
Explanation
Oxygen makes up about 21% of Earth's atmosphere. Combustion requires oxygen — without it, fire goes out. Pure oxygen at high concentrations is toxic to humans, but too little causes hypoxia and death.
This is an easy riddle in the Science category — Riddles about physics, space, biology and the laws of the universe.
Tags:sciencechemistrylife
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