CHE-1101 Chapter Notes - Chapter 2: Carbon-12, Cathode Ray Tube, Subatomic Particle
Document Summary
Leucippus and democritus believed all matter was composed of small, finite particles called atomos. Aristotle believed matter consisted of combinations of the four elements fire, earth, air, and water. All matter is made up of atoms, which are the smallest units of an element. All atoms of the same element are identical. Compounds consist of atoms of two or more elements combined in small, whole-number ratio. Law of definite proportion and law of multiple. Chemical reactions are rearrangements of atoms to form new products. Late 1800"s: j. j thomson & cathode ray tube. Thomson found the first subatomic particle - the electron did not find the positively charged part. Said the atom was like plum pudding a positively charged mass with an equal negative charge in the form of electrons (atoms are neutral) Determined the charge of a single electron and subsequently the mass (charge to mass ratio known from thomson)
