ISCI 101 Study Guide - Final Guide: Bohr Model, Atomic Nucleus, Electron Rest Mass

• School: JMU
• Department: Interscience Research
• Course: ISCI 101
• Professor: yanjiezhang

Document Summary

Most of the atom"s mass & all of the positive charge are concentrated at the nucleus. Bohr atom: bohr proposed that the max number of electrons in any one orbit equal 2n 2 n = number of orbit. Nucleus of atom: diameter of the atom is ~100,000x greater than diameter of nucleus. Atomic number: number of protons in nucleus of atom = number of electrons in atom. Mass number: number of protons + number of neutrons. Atomic radius: average distance from center of atomic nucleus to outer surface. Atomic mass scale based on assigning the mass of the carbon-12 isotope, exactly 12 atomic mass units (amu) Isotopes: atoms of the same element having different mass number; have the same number of protons & electrons, different number of neutrons. Valance electrons: the outmost electrons in an atom involved in forming chemical bonds. Most properties of an atom are defined by its valance electrons.