What is said about the Law of Definite Proportions by Joseph Proust?
A given combination will always include exactly the same amount of each element in terms of weight.
A certain compound always has exactly the same amount of moles by weight.
A particular compound always has the exact same volume ratio of the constituents in it.
A given compound always has exactly the same amount of each constituent in terms of weight.
When Joseph Proust worked about the composition of elements present in a compound experimentally, he found out that it was the same for all the samples he took. Joseph Louis concluded that from any source, a particular compound always contains the same elements in the same proportion by mass/weight.