CHEM 1B Lecture Notes - Lecture 1: Empirical Formula, Oatmeal, Mass Spectrometry
Document Summary
The atom as a nucleus with orbital electrons (nuclear model) Atomic mass and the mass spectrometer (average atomic mass and relative abundance) Chemistry is central to our fundamental understanding of science-related fields. Chemistry is how matter is organized/reorganized/changed at a molecular level. In the environment: sea salt, airborne dust, laboratory, smog particles. Matter (may be solid, liquid, or gas) anything that occupies space and has mass: heterogeneous matter: non-uniform composition (oatmeal, sand in water) Physically separable into homogeneous matter: homogeneous matter: uniform composition throughout (saltwater, wine) Substances: fixed composition; cannot be further purified. Elements: cannot be subdivided by chemical or physical change: monatomic: particles are atoms (na and ne, diatomic: particles are molecules (h2o) A sodium chloride crystal i a symmetrical array of sodium ions and chloride ions in a 1:1 ratio. The sum of the charges on the cation(s) and anion(s) in each formula unit must equal zero.
