Atomic Theory: Democritus, Conservation Laws, Dalton's Theory, Slides of Chemistry

Download Atomic Theory: Democritus, Conservation Laws, Dalton's Theory and more Slides Chemistry in PDF only on Docsity! Atoms Docsity.com Atoms • Greek philosopher, Democritus fifth century B.C., coined term atom, as particles that can not be cut or broken up further. Docsity.com Law of Definite Proportions • Many compounds are made of more than one element • Each element has the same proportion in a compound, regardless of where it was made Docsity.com Joseph Proust • Copper carbonate from various sources always had same composition • Always 36.18% oxygen, 57.48% copper, 5.43% carbon and 0.91% hydrogen Docsity.com Law of Definite Proportions • A compound always contains the same elements in certain definite proportions and no other combinations. Docsity.com Modern Modifications 1. Atoms not completely indivisible 2. Not all atoms of an element are completely alike 3. Number of atoms in a molecule usually a simpler ratio Docsity.com Example • Jons Berzelius found • 10g lead + 1.55g sulfur --- 11.55g Pbsulfate Docsity.com