CHEM 154 Lecture Notes - Lecture 2: Oil Analysis, Electron Excitation, Atomic Orbital
Document Summary
Science of compositions, structure, and properties of matter and how they change (transformations) Electrons are light (small), far from nucleus, and important to identifying properties (reactivity, bonding) Cannot add quantity of protons, neutrons, and electrons to simply solve for mass. Atoms of larger/smaller charge due to added/lost electrons. Never add or remove protons to change charge, only electrons can be gained or lost. The periodic table arranges elements according to number of protons as well as the number/arrangements of electrons. Bohr model - determine max electrons in particular orbit. Number electron = 2n^2 (n=1, 2, 3 orbit) Believed electrons orbit nucleus in perfectly defined orbits. Excellent at predicting energy of one-electron species. Energy is quantized (discrete - only certain values, not continuous, nothing in between) Electrons in lower n orbits are more stable (lower energy. Electrons in lower energy orbit (n) can be excited to high level orbits. Atoms can be excited by exposure to light.
