Helium is the creation of most solar fusion. When hydrogen atoms are squished tightly enough together, they combine into helium atoms in the process of nuclear fusion, which releases the energy that powers you and everything else on Earth!
When you have water in a bottle and there’s a bubble of air in it, the bubble always goes to the highest part of the bottle — because air is less dense than water. That’s the same reason helium balloons float. Helium is less dense than air, so it’s like an air bubble in the water bottle of the atmosphere. (The diameter is calculated from the van der Waals radius.)
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