NATS 1945 Lecture Notes - Lecture 2: Brownian Motion, Nanometre, Atomic Number

• School: York University
• Department: Natural Science
• Course: NATS 1945
• Professor: Robin Metcalfe

Document Summary

Part 1: atoms and the periodic table: all matter is made up of unsliceable particles called atoms, democritus" concept of atom, an atom contains: A nucleus of protons ( + charge) and neutrons ( 0 charge) If the ion has more protons than electrons, the net electric charge is positive. If the ion has more electrons than protons, the net electric charge is negative: molecule: a group of atoms bound together, chemical reaction: when molecules break apart and recombine to form new molecules. Molecule combinations change: size of an atom: ~0. 1 nanometre. Too small to be seen, but can be detected by the boundaries of their individuals electric elds. Part 3: molecular vibrations and temperature: brownian motion, molecules vibrate within microscopic distances (~10-6m) and at ~sound speed (330m/ s) Visible in uids ( brownian motion ) by microscope. Explains how earth"s atmosphere lost most of its h and he.