CHE 106 Lecture Notes - Fall 2018 Lecture 6 - Metalloid, Unified atomic mass unit, Semimetal

• School: Syracuse University
• Department: Chemistry
• Course: CHE 106
• Professor: Professor Weiwei Zheng

Document Summary

Lecture 6: atomic weights, periodic table, molecules, compounds. Rutherford: the nuclear atom: rutherford postulated a very small, dense positive center with the electrons around the outside. Most of the atom is space: atoms are very small; 1-5 or 100-500 pm, other subatomic particles (protons and neutrons in the nucleus) It is written as a subscript before the symbol. 6 is the atomic number for carbon: the mass number is the total number of protons and neutrons in the nucleus of an atom. It is written as a superscript before the symbol. Atomic weights: dalton"s relative atomic masses, dalton devised experiments to measure their masses relative to the hydrogen atom. Dalton assigned hydrogen a mass of 1 amu. (mass of a h atom (1 proton + 1 electron) = 1. 674 x 10-24g: dalton"s atomic weight scalee was eventually replaced by the present carbon-12 mass scale in.