substance. A sample of matter that cannot be separated into simpler components without chemical change. Physical changes can alter the state of matter but not the chemical identity of a pure substance. Pure substances have fixed, characteristic elemental compositions and properties.
is a substance that has a fixed chemical composition throughout.
a form of matter that has a definite composition and distinct properties
a homogeneous collection and has associated parameters such as mass, volume, temperature and specific volume that are constant throughout the substance
a substance that contains only one kind of matter; elements and compounds are pure substances raw materials processed material that can be converted by manufacture, processing, or combination into a new and useful product
matter with a constant molecular formula free of "contamination" by other elements.
A substanceâ€”either an element or compoundâ€”that has an unvarying composition. This means that by changing the proportions of atoms, the result would be an entirely differentsubstance. Compare with mixture.