No - a star would not be a pure substance. Our understanding of how stars function includes a continuous fusion of hydrogen to form helium and, depending on the star, possibly further fusion of the helium into even heavier elements. Once formed, these heavier elements do not just go away or change back into helium so stars will always be composed of a mixture of hydrogen and the byproducts of fusion.
pure substance, propanone
it is a pure substance.... not
Pure substance
Methane is a pure substance.
pure substance
pure substance
Pure Substance
A pure substance is classified by having a definite and constant composition. The substance can be either an element or a compound, but what makes the substance pure, is that it does not vary.
Neon is a pure substance. Elements and compounds are pure substances; mixtures are not.
CH3COOH is a pure substance. It is the chemical formula for acetic acid.
Refined substance can be a pure substance depending on the type of sugar used. If the refined sugar is white, then it is a pure substance. If it the refined sugar is brown, then it is not a pure substance.
pure substance?