What are the two methods fusion occurs within a star?

the proton-proton chain and the carbon-nitrogen-oxygen (CNO) cycle

Explanation:

Because liquids flow freely, they take the shape of the container they are in, but have a definite volume. Like liquids, the shape of a gas changes with the container. This is because the atoms in a gas move rapidly and freely to fill any available space. Unlike liquids, the volume of a gas changes depending on the container it is in.

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