CHEM 131 Lecture Notes - Lecture 2: Cathode Ray, Spontaneous Emission, Nuclear Transmutation

• School: Towson University
• Department: Chemistry
• Course: CHEM 131
• Professor: Shuhua Ma

Document Summary

Dalto(cid:374)"s ato(cid:373)ic theor(cid:455: atoms, compounds, chemical reaction. The discovery of atomic structure: cathode ray experiment, measured charge/mass of electrons (negative charged ions) Radioactivity: spontaneous emission of radiation by an atom, 3 types of radiation. Rays high energy particles without charge. Rutherford"s e(cid:454)peri(cid:373)e(cid:374)t: ato(cid:373)"s positive charge is co(cid:374)ce(cid:374)trated i(cid:374) the (cid:374)ucleus, proton has opposite charge of electron, mass of proton is 1840 x mass of electrons (1. 67 x 10-24g) Rutherford"s model of the ato(cid:373: a very small, dense nucleus surrounded by the electrons of the atom. The modern view of atomic structure: protons were discovered by rutherford in 1919, neutrons were discovered by james chadwick in 1932, mass (p) ~ mass (n) ~ 1840 x mass (e-, atom. Number of protons = number of electrons. Give the number of protons, neutrons, and electrons in each of the following species: 11, 11. Electrons 8: carbon 14 = 14c. Radioactive reaction: radio decay, nuclear transmutation.