CHEM 1110 Chapter Notes - Chapter 2: Hydronium, Roman Numerals, Nsb Di 2
13 Sep 2016
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Cathode rays the study of electrical discharge. Originated at negative then went to positive. Electron mass = 1. 602 x 10^-19 c / 1. 76 x 10^8 c/g = 9. 10 x 10^-28 g. Radioactivity henry becqerel ( a ) alpha ( b) beta ( y ) gamma. Plum pudding model of an atom j. j thompson. After the gold foil experiment he found the plum pudding model to be false. Because some of the particles bounced back off something in the middle, the nucleus was discovered: nucleus extremely dense region with positive particles (the neutrons in the nucleus were discovered at a later time) Angstrom a si unit for atomic distance. Atomic mass unit (amu) they weigh so little that this is the only unit we can measure them efficiently. Atomic number the number of protons an element has (neutrons vary, electrons equal) Isotopes an element has a different number of neutrons/mass number varies but protons stay the same.
