CHM 23000 Lecture Notes - Robert Andrews Millikan, Amedeo Avogadro, Unified Atomic Mass Unit

• School: Lindenwood University
• Department: Chemistry
• Course: CHM 23000
• Professor: Professor Delgado

Document Summary

Dalton"s atomic theory: all matter is made up of tiny particles called atoms, atoms of the same element are chemically alike, atoms cannot be created, destroyed or subdivided, atoms combine in small whole number ratios. In chemical reactions, atoms are separated, rearranged, and/or combined. Atom smallest piece of matter that can still be identified as that matter. Notified a stream of negatively charged particles emitted from an anode. Realized all had same mass and charge. Mass of electron is 1/2000th mass of h atom. Confirmed negative charge 9. 109 x 10-31 kg (mass of electron: where does mass of the atom come from. Must be more massive particles in the atom: electrons are negatively charged, but the whole atom is neutral. P+ stay together in nucleus due to strong & weak nuclear forces. Atomic # (z) # of protons in the atom. Atomic mass average mass in amu"s of all atoms of that element.