Is pure Iron a pure substance or mixture

Pure iron is a pure substance.

Explanation:

Pure iron is a pure substance because it's chemical composition stays uniform regardless of it's sample size. It's matter that appears uniform in appearance and composition, no matter how small the sample size. An example of a pure substance includes pure iron

no, the red giant is the hottest with 2.00.000.000 degrees celsius. while the white dwarf only 25,000 degrees celsius.