Orbital Filling Electron Configurations

1. Orbital FillingElectron Configurations Where do these electrons go?

2. Aufbau Principle • Orbitals are filled from lowest energy to highest energy • Orbitals closest to the nucleus contain lower energy • They are filled first

3. Orbital Energies Lowest to Highest

4. Orbital Diagrams • Shows the distribution of electrons within orbitals • Circles/Lines/Boxes are used to represent the different orbitals • Arrows are used to represent single electrons

5. Orbital Diagram for Hydrogen 1s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy

6. Orbital Diagram for Helium 1s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy

7. Orbital Diagram for Helium 1s • Pauli Exclusion Principle • Each orbital can only contain two electrons • These electrons must be distinguished from one another (“opposite spin”) • One arrow up, One arrow down

8. Orbital Diagram for Lithium 1s 2s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy

9. Orbital Diagram for Boron 1s 2p 2p 2p 2s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy • The first “p” sublevel • When the sublevels are drawn, all orbitals within that sublevel must be drawn

10. Orbital Diagram for Carbon 1s 2p 2p 2p 2s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy • When the sublevels are drawn, all orbitals within that sublevel must be drawn

11. Orbital Diagram for Carbon 1s 2p 2p 2p 2s • Hund’s Rule • Electrons will not pair up within orbitals until each orbital within a sublevel contains at least one electron • Electrons distribute “evenly”

12. Orbital Diagram for Neon 1s 2p 2p 2p 2s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy • All orbitals within the highest sublevel level are completely filled

13. Orbital Diagram for Phosphorus 1s 2p 2p 2p 2s 3s 3p 3p 3p • Aufbau Principle • Hund’s Rule

14. Orbital Diagram for Potassium 1s 2s 2p 2p 2p 3s 3p 3p 3p 4s • Aufbau Principle • Orbitals are filled from lowest energy to highest energy

15. Orbital Diagram for Vanadium 1s 2s 2p 3p 2p 3s 3p 3p 2p 4s 3d 3d 3d 3d 3d Hund’s Rule • Aufbau Principle • Orbitals are filled from lowest energy to highest energy • When the sublevels are drawn, all orbitals within that sublevel must be drawn

16. Electron Configurations • A short hand way of representing the “location” of electrons around the nucleus • Not as much detail as orbital diagrams, but a convenient way of showing patterns for groups of elements on the periodic table

17. Electron Configuration for Hydrogen 1s 1s1

18. Electron Configuration for Helium 1s 1s2

19. Electron Configuration for Carbon 1s 2p 2p 2p 2s 1s2 2s2 2p2

20. Electron Configuration for Neon 1s 2p 2p 2p 2s 1s2 2s2 2p6

21. Electron Configuration for Phosphorus 1s 2p 2p 2p 2s 3s 3p 3p 3p 1s22s22p63s23p3

22. Electron Configurations for… • Hydrogen • Helium • Lithium • Boron • Carbon • Neon • Sodium • Phosphorus • Argon • Potassium • Vanadium • Manganese

23. Patterns in Electron Configurations • All elements within the same column have the same “ending” for their electron configuration • All end with electrons in the same sublevel, but different principal energy level • These elements all belong to the same “family” or “group” • They exhibit similar chemical properties • Due to their similar electron configurations, which will be discussed in more detail in later chapters

24. Groups of Elements & Electron Configurations