CHM 101 Lecture Notes - Lecture 2: Subatomic Particle, Heavy Water, Atomic Theory
Document Summary
Atomic theory & understanding the atom: sec 2. 1-2. 2. Atomic theory of matter: john dalton (1808: all matter is composed of tiny particles called atoms, all atoms of a given element are identical, but atoms of different elements differ in size, mass, and chemical properties, ex. Law of definite proportions: a particular compound will always have the same chemical composition. A water molecules is always made up of two hydrogens and one oxygen, h2o. Doesn"t matter where you are, on earth or mars, a water molecule (ex) will always have 2 hydrogen atoms and 1 oxygen (h2o) Law of conservation of mass: no matter can be created or destroyed, called mass balance . Mass of 1 element combines with fixed mass of other elements. Compounds are formed when atoms of different elements unite in fixed proportions. Electrons: negatively (-) charged particles that exist in a large. Cloud around the nucleus, 1st subatomic particle found. Occupy large space, but atoms are small.
