Warm-Up Turn in your Flame Test Lab! How can you determine how many electrons are in an atom? How do those electrons like to fill up orbitals in an atom?

Orbital Notation

Aufbau Principle Electrons fill the lowest available energy orbital before filling higher energy orbitals

Pauli Exclusion Principle In a single atom, two electrons cannot have the same set of 4 quantum numbers

Hund’s Rule When filling degenerate orbitals, each orbital is singly occupied before any orbital is doubly occupied. All electrons in singly occupied orbitals have the same spin.

Energy Filling Diagram

Hydrogen Number of Electrons = 1

Helium Number of Electrons = 2

Lithium Number of Electrons = 3

Boron Number of Electrons = 5

Carbon Number of Electrons = 6

Oxygen Number of Electrons = 8

Scandium Number of Electrons = 21

Silicon Number of Electrons = 14

Potassium Number of Electrons = 19

Warm-Up Write the orbital notations for the following 3 elements: I am stamping your Orbital Notation Notes (HW)! Write the orbital notations for the following 3 elements: Phosphorus Magnesium Krypton

Homework Answers

Electron Configurations An abbreviated version of orbital notations Each sublevel is grouped together! s holds 2 electrons p holds 6 electrons d holds 10 electrons f holds 14 electrons

Examples Nitrogen: 7 electrons Phosphorus: 15 electrons 1s22s22p3 Phosphorus: 15 electrons 1s22s22p63s23p3 Scandium: 21 electrons 1s22s22p63s23p64s23d1

Examples Iridium: 77 electrons Xenon: 54 electrons 1s22s22p63s23p64s23d104p65s24d105p6 6s24f145d7 Xenon: 54 electrons 1s22s22p63s23p64s23d104p65s24d105p6 Potassium: 19 electrons 1s22s22p63s23p64s1

Examples Cobalt: 27 electrons Silicon: 14 electrons 1s22s22p63s23p64s23d7 Silicon: 14 electrons 1s22s22p63s23p2 Cadmium: 48 electrons 1s22s22p63s23p64s23d104p65s24d10

Warm-Up I am stamping your HW! Write the electron configurations for the following elements: Hydrogen Lithium Potassium Carbon Silicon Tin (Sn)