Single chemical element, single phase (usually solid), but different 3D structures.
We define a "sugar" as either of:because these are small carbohydrates, and they taste sweet to humans.
The most important on in metabolism internals, everything else gets converted to it before being processed in the .
en.wikipedia.org/w/index.php?title=Nutrient&oldid=1075972831#Essential gives somewhat of an overview:
Mentioned at 100 Greatest Discoveries by the Discovery Channel (2004-2005) medicine episode.
Active compound in pepper.
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A chemical substance is matter identified by a characteristic chemical composition and set of chemical properties. It can be an elemental substance, such as molecular nitrogen, or a chemical compound, such as water. A mixture instead contains components whose proportions can vary without requiring a different compound identity.
Composition alone may not specify the physical form. Diamond and graphite are elemental carbon with different bonding networks, and a single compound can have several crystalline phases. Describing a sample therefore calls for both chemical identity and, when relevant, its phase, structure, and purity.