CHY 102 Lecture Notes - Lecture 1: Hot Cathode, Mass Number, Alpha Particle
14 Sep 2016
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Document Summary
The world is empty space with tiny particles called atomos which means indivisible. The greeks believed that matter is composed of tiny indestructible particles they called atoms. Matter is made up of elements such as earth, water, air and fire. Observed that chemical change didn"t involve a change in mass. Law of conservation of mass-in a chemical reaction, the mass of the products is equal to the mass of the reactants. Law of definite proportions - substances contain elements in fixed ratios by mass. Dalton"s model of the atom was a solid sphere. % c = mass of c/total mass x 100. N=14/17=0. 824 mass of c is 27. 3% mass of n is 82. 4% All the atoms of an element are not identical. Even though their chemical properties are alike, they differ somewhat in their mass. These atoms of the same element with different masses are called isotopes. All atoms of one element are not the same mass.
