Wiktionary
n. A material with a specific chemical composition.
Wikipedia
A chemical substance is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be chemical elements, chemical compounds, ions or alloys.
Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt ( sodium chloride) and refined sugar ( sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical.
Chemical substances exist as solids, liquids, gases or plasma, and may change between these phases of matter with changes in temperature or pressure. Chemical reactions convert one chemical substance into another.
Forms of energy, such as light and heat, are not considered to be matter, and thus they are not "substances" in this regard.
Usage examples of "chemical substance".
One, a flattened bottle which contained a chemical substance, identified after analysis as lauric-mono ethanol amide stearic diethanolamine sorbatin trio late the other item was a crumpled piece of paper with a series of dots drawn on it, which I believe to be a star chart.
Pineapples naturally contain a chemical substance that inhibits jelling.
This need not be a chemical substance at all in the ordinary sense of the word.
In the same kind of way, every musical composition is built ultimately from the same set of notes, and every chemical substance from the same three subatomic particles.
But it is interesting that it would be, in principle, possible (I think) for a physicist to synthesize any chemical substance that the chemist writes down.
You expose one chemical substance and another to the emanations of radium, and see what happens.
His life had been built on battles, and: if he were to lose one to a mere chemical substance when he had won so many against tough human adversaries, it was all a sham.
He didn't know for sure from that one quick glance if they were out of their minds, high on some chemical substance, or strung out, desperate and ready to eliminate anyone who so much as looked at them crooked.
In a moment a trampled Python, the fever,was vanquished by the potent chemical substance to which my grand-mother, across the series of kingdoms, reaching out beyond all animal andvegetable life, would fain have been able to give thanks.
Crusher has found traces of an unknown chemical substance, a drug, in the Choraii atmosphere, which has affected him.
When Enderby got by taxi to the hotel he found a fire engine there, summoned from Indianapolis, with the firemen pumping not water but a grey chemical substance over all available surfaces.