CHEM103 Chapter Notes - Chapter 2: Atomic Mass, Atomic Number, Relative Atomic Mass

• School: University of Alberta
• Department: Chemistry
• Course: CHEM103
• Professor: Veinot( G)

Document Summary

Law of conservation of mass mass of substances produced by a chemical reaction is always equal to the mass of the reactants. Law of constant composition/law of definite proportions a chemical compound always has the same elemental composition by mass. All chemical elements are made up of atoms which are indivisible and indestructible during a chemical change: all atoms of a given element are identical in mass and properties. Elements combine in a simple numerical ratio to form compounds. Law of multiple proportions when two elements combine, the ratios of the masses of one element that combines with the fixed mass of the other are small whole numbers. Radioactivity alpha particles ( ) two units of positive charge. Beta particles ( ) one unite of negative charge. Gamma rays ( ) electromagnetic radiation with high penetrating power. Three subatomic particles: protons (+), electrons (-), neutrons (neutral)