Chemistry 1027A/B Study Guide - Lyman Series, Bohr Model, Antibonding Molecular Orbital
Document Summary
Atoms are the building blocks of all elements. Neutrons (neutral) and protons (+ve) reside in the nucleus whereas electrons (-ve) occupy the area around the nucleus. Protons and neutrons have almost the same mass; an electron is about 1/2000th of their mass. All atoms of the same element have the same number of protons in the nucleus. The number of protons in an atom is the atomic number. The mass number is the total number of protons and neutrons in an atom. Mass number = number of protons + number of neutrons. Isotopes: atoms with the same number of protons but different number of neutrons; isotopes have the same atomic number but a different mass number. Isotopic abundance: is the percent by number of each of the isotopes of an element. Average atomic mass = percent of isotopic abundance 100 x isotopic mass.
