Electron Configuration

Activity Make three large sheets with a different element on each. Each sheet will have electron configuration, Bohr model with dots, and orbital diagram of that element. Students will do a gallery walk and put sticky notes under three categories; I know, I wonder, I discovered.

Simple model of a potassium atom Electron Structure In a neutral atom, electrons = atomic number. Electrons are arranged into energy levels. Energy Level (shell) defines how far the electron is away from the nucleus. n = 1 n = 3 n = 4 More Energy Nucleus n = 2 Simple model of a potassium atom

Quantum Numbers 4 numbers that define the location and movement of the electrons. Principle Quantum number (n) Orbital Angular Momentum Quantum number (l) Magnetic Quantum number (ml) Spin Quantum number (ms)

Principle Quantum number (n) = Energy Level (shell) defines how far the electron is away from the nucleus.

Orbitals Shells are divided into subshells (orbitals). Orbital Angular momentum quantum number (l) – defines the shape of the sublevel (orbital). Four types: (named after spectroscopic groups of lines before quantum mechanics) Energy Level (shell) (angular momentum) s (sharp) (l=0) p (principal) (l=1) d (diffuse) (l=2) f (fundamental) (l=3)

Magnetic quantum number (ml) – defines the orientation in space of the orbital. s, p, d, and f orbitals

Electron Spin Spin Quantum number (ms) – designates direction of electron spin. Each orbital can hold up to 2 electrons. Why only 2 in each orbital? Spin up Spin down Stern-Gerlach Experiment

Video Video – Electron Spin Explained

Electron Structure n=1 n=2 n=3 n=4 s l=0 1s 2s 3s 4s p l=1 2p 3p 4p Shells and orbitals n=1 n=2 n=3 n=4 s l=0 1s 2s 3s 4s p l=1 2p 3p 4p d l=2 3d 4d f l=3 4f

Electron Structure Orbitals s / 1 orbital / 2 electrons p / 3 orbitals / 6 electrons d / 5 orbitals / 10 electrons f / 7 orbitals / 14 electrons

Electron Configurations 3p 3d 4d 5d 6d 2p 4p 5p 6p 7p 4f 5f 1st row 2nd row 3rd row 4th row 5th row 6th row 7th row Row number – 1 Row number – 2

Electron Configurations What is the electron configuration for H? H has 1 e- What is the electron configuration for He? He has 2 e- 1s1 1s2

Electron Configurations What is the e- config. for lithium? What is the e- config. for oxygen? 1s2 2s1 1s2 2s2 2p4

Electron Configuration Practice thru period 3 Board

Electron Structure Aufbau Principle – Electrons fill lowest sublevels first. Aufbau = German for “building up”. Energy levels overlap. Expected order: 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f... Actual order: 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f...

Aufbau Principle 6p 5d 4f 6s 5p 4d 5s 4p Increasing Energy 3d 4s 3p 3s

Electron Configurations 3p 3d 4d 5d 6d 2p 4p 5p 6p 7p 4f 5f 1st row 2nd row 3rd row 4th row 5th row 6th row 7th row Row number – 1 Row number – 2

Electron Configuration 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p

Electron Configurations What is the e- config. for iron? What is the e- config. for iodine? 1s2 2s2 2p6 3s2 3p6 4s2 3d6 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p5

Electron Configuration Practice after period 3 Board

Noble Gas Configuration Noble gases: Group 8A He, Ne, Ar, Kr, Rn, Xe, element 118 e- configuration for Mg (element 12): 1s2 2s2 2p6 3s2 e- configuration for Ne (element 10): 1s2 2s2 2p6 Noble gas configuration for Mg: [Ne] 3s2

Noble Gas Configuration To write NGC: Find your element. Find the noble gas (Group 8A) before your element. Write the noble gas in brackets. Add electrons to the noble gas until you reach your element.

Noble Gas Configuration Write the NGC for bismuth (element 83) Previous noble gas: xenon (element 54) Bismuth is on row 6, so start with 6s2. Brings the total up to 56. Proceed to 4f14. Brings the total up to 70. Proceed to 5d10. Brings the total up to 80. Proceed to 6p3. Brings the total up to 83. Done! [Xe] 6s2 4f14 5d10 6p3

Noble Gas Configuration Write the NGC for radium (element 88) Previous noble gas: radon (element 86) Radium is on row 7, so start with 7s2 Brings the total up to 88. Done! [Rn] 7s2

Noble Gas Configuration Practice Board

Configuration Practice Sheet