CH-1010 Lecture Notes - Lecture 4: Cathode Ray Tube, Robert Andrews Millikan, Atomic Number
Document Summary
Atoms are the fundamental building blocks (smallest particles) of matter. Model is consistent with observation (laws) and explains behavior of matter. Compounds always contain the same proportions of their component elements. When 2 elements combine to make two (or more) compounds, the ratio of the masses of the first element, which combine with a given mass of the second element, is a ratio of small whole numbers. Dalton concluded that elements combined according to the law of multiple proportions because they were composed to atoms. Dalton"s atomic theory proposed that atoms were the smallest units of matter, but by the end of the 19th century, scientists began to suspect that atoms were made up of even smaller subatomic particles. Charge/mass ratio same for all cathodes (i. e. all elements) Electrons are present in all elements e/m = -1. 75882028 x 108 c/g.