Presentation on theme: "Isotope Formulae, Electron Configurations & Orbital Diagrams"— Presentation transcript:
1Isotope Formulae, Electron Configurations & Orbital Diagrams
2Isotope Formulae Provide element’s symbol Mass number Atomic number mass# = #p+ + #nwritten as a superscript to the leftAtomic numberatomic# = #p+ or #e-written as a subscript to the left
3X C C Isotope Formulae Mass# Atomic# 12 6 13 6 Carbon has two naturally occurring isotopes:carbon-12 and carbon-13C126C136
4Isotope FormulaeGive the isotope formula for each of thefollowing:H311. Hydrogen with 2 neutronsF1892. Fluorine with 9 neutronsU235923. Uranium with 143 neutrons
5Valence Electron(s)The electron(s) farthest from the nucleus or in the outermost energy level.
6Aufbau Principle Comes from German word meaning “to build” Electrons will occupy lower energy orbitals first
7Pauli Exclusion Principle An atomic orbital can hold at most two electrons.If an atomic orbital holds two electrons, they must have opposite spins.
8Hund’s RuleWhen filling atomic orbitals of equal energy, place electrons with parallel spins in the orbitals first. Then, place the oppositely spinning electrons in to the orbitals.
9Electron Configurations Also describe where electrons live within an atomIt’s like a translation of quantum numbers.They give the energy level, atomic orbital, and number of electrons residing in the orbital and energy level.
10Electron Configurations Energy levelMay be any positive integerJust like the principal quantum number
11Electron Configurations Atomic Orbital or SublevelRepresented by letters: s, p, d, fTranslates azimuthal number and magnetic numbers is the same as l = 0p is the same as l = 1d is the same as l = 2f is the same as l = 3
12Electron Configurations Number of Electronsin either an atomic orbital or a sublevelmax of 2 in the s sublevelmax of 6 in the p sublevelmax of 10 in the d sublevelmax of 14 in the f sublevel
13Electron Configurations Use the periodic table to guide you in writing electron configurations.Find the link between 2,6,10, and 14 and the periodic table.
14Electron Configurations Hydrogenenergy level1s1# of electronssublevel/orbital
15Electron Configurations Write the e- configurations of the next 9 elements (through Ne).He…1s2Li…1s22s1Look at the sumof the superscripts…Be…1s22s2B…1s22s22p1
24Orbital DiagramsShow the electron configuration while illustrating the Aufbau Principle, Pauli Exclusion Principle, and Hund’s RulePlace energy on the y-axisUse lines to represent orbitalsUse up and down arrows to indicate spin