In chemistry, the law of definite proportions, sometimes called Proust's Law, states that a chemical compound always contains exactly the same proportion of elements by mass. An equivalent statement is the law of constant composition, which states that all samples of a given chemical compound have the same elemental composition by mass. For example, oxygen makes up about 8/9 of the mass of any sample of pure water, while hydrogen makes up the remaining 1/9 of the mass. Along with the law of multiple proportions, the law of definite proportions forms the basis of stoichiometry.
Read more about Law Of Definite Proportions: History, Non-stoichiometric Compounds
Famous quotes containing the words law of, law, definite and/or proportions:
“What, then, is the true Gospel of consistency? Change. Who is the really consistent man? The man who changes. Since change is the law of his being, he cannot be consistent if he stick in a rut.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
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“It is not growing like a tree
In bulk, doth make man better be,
Or standing long an oak, three hundred year,
To fall a log at last, dry, bald, and sere:
A lily of a day
Is fairer far in May
Although it fall and die that night;
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In small proportions we just beauties see,
And in short measures life may perfect be.”
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