Presentation on theme: "The Quantum Mechanical Model"— Presentation transcript:
1 The Quantum Mechanical Model The nucleus is found inside a blurry “electron cloud”A area where there is a high probability of finding an electron.
2 *No more than 2 electrons in each orbital* Electron ConfigurationPrincipal Quantum Number (n) = the energy level of the electron. (max # e- = 2n2 )Sublevels- like theater seats arranged in sections (s,p,d,f) (# of sublevels = n )Within each energy level, the complex math of Schrodinger’s equation describes several shapes.These are called atomic orbitals - regions where there is a high probability of finding an electron*No more than 2 electrons in each orbital*
3 Summary # of orbitals Max electrons Starts at energy level sublevel s 121p362d51037144f
4 Relative sizes of the spherical 1s, 2s, and 3s orbitals of hydrogen.
7 Electron Configurations The way electrons are arranged in atoms.Three main “guiding” principles:Aufbau principle- electrons enter the lowest energy first.
8 Electron Configurations Pauli Exclusion Principle- at most 2 electrons per orbitalWhy only 2 electrons per orbital?like charges repel each other, but…electrons spin on axis,clockwise or counterclockwise,creating magnetic polarization ( ↑↓ )
9 Hund’s Rule- When electrons occupy orbitals of equal energy (same sublevel ) they don’t pair up until they have to.- one electron enters each orbitaluntil all orbitals contain one electronwith spins parallel.
10 Writing Electron Configurations (Letter - number designation)# of e-H1s1SublevelPrinciple Energy Level
11 Orbital Diagrams ↑ ↓ ↑ ↓ ↑ ↑ ↑ N 1s 2s 2p 2 2 3 Show each orbital as a circle, box, or line.Show each electron as an arrow, ↑ or ↓ spin.Label electron configuration (letter –number).↑↓↑↓↑↑↑N71s2s2p223
12 Increasing energy 7p 6d 5f 7s 6p 5d 6s 4f 5p 4d 5s 4p 3d 4s 3p 3s 2p Orbital (Aufbau) diagram
13 ExampleLet’s determine the electron configuration & orbital diagram for PhosphorusNeed to account for 15 electrons
14 Increasing energy 7p 6d 5f 7s 6p 5d 6s 4f 5p 4d 5s 4p 3d 4s 3p 3s 2p
15 Orbitals being filled for elements in various parts of the periodic table.
16 Remember…When we write electron configurations, we are writing the lowest energy (ground state) configuration.Do Problems pg 160*** # 21 draw orbital diagrams,not just e- configurations