1. Electrons In Atoms

2. Electromagnetic Radiation Form of energy that exhibits both wavelike behaviors and particle behaviors

3. Electromagnetic Spectrum Shows all forms of electromagnetic radiation

6. Quanta Electrons gain/lose energy in set increments only Each set amount of energy is called a quantum Lost energy is released as electromagnetic radiation, with more energy = higher frequency

7. Photoelectric Effect Emission of electrons from metal’s surface when light of specific frequency shines on surface METAL light e-e-

8. Wrap-Up #1 If electrons will only be emitted by light of high energy, which of the following is more likely to release electrons? –Blue light with low intensity (dim) –Red light with high intensity (bright) –Radio waves with high intensity

9. Bohr Model – Electron States Ground State –Lowest energy state of an electron –Where the electron is “naturally” Excited State –State when an electron gains energy –Only exists while energy is being absorbed by the atom Glow in the dark materials – the electrons absorb energy from light and re-release it as light when its surroundings are dark

10. Bohr Model E1E1 E2E2 E3E3 E 1 = lowest energy level E 3 > E 2 > E 1

11. Ground State to Excited State 1.in ground state, no energy radiated 2.in excited state, electrons jump to higher energy level (because they’ve absorbed energy from an external source) 3.electrons go from high E level to low E level 4.photon emitted 1 2 3 4 5 6 Energy of atom 1 2 3 4

12. Atomic Orbitals Volume surrounding the nucleus in which an electron is 90% likely to be found

13. Principle Quantum Number (n) Indicates the energy level an electron is on –Use periodic table to tell –The period number corresponds to the principle quantum number (n = 1,2,3…)

15. Energy Orbitals Shape of orbital that tells the path of the electrons –4 orbitals: s, p, d, f –The letter tells you the shape of the orbital

16. s orbital Shape: electrons travel in a sphere

17. s orbital 1s 2s 3s The greater the energy level, the bigger the orbital

18. p orbital Shape: dumbbell or figure 8 shaped

19. d orbital Shape – double dumbbells or a dumbell with a ring around it

20. Electron Configuration Description of the arrangement of electrons in an atom Allows us to visualize where the electrons in an atom can be found

21. Rules Governing Electron Configurations 1) Aufbau Principle – electrons occupy lowest energy orbital available - fill up level 1 first, then level 2, etc. 2) Pauli Exclusion Principle – there is a max number of electrons that occupy a single orbital (2) and they must have opposite spin

22. Rules Governing Electron Configurations 3) Hund’s Rule – if orbitals have equal energy, one e - will go in each orbital before doubling up 12 4 3 56

23. Rules Governing Electron Configurations 3b) Hund’s Rule – all electrons in singly occupied orbitals must have the same spin Yes NO Yes

24. Blocks On Periodic Table s d p f s

25. Divisions of Orbitals s orbital – 1 sublevel (2 e - max) p orbital – 3 sublevels (6 e - max) d orbital – 5 sublevels (10 e - max) f orbital – 7 sublevels (14 e - max)

26. Orbital Diagram Nitrogen How many electrons? 7 1s2s2p

27. Orbital Diagram Silicon How many electrons? 14 1s2s2p3s3p

28. Wrap-Up #2: Orbital Diagram Copper How many electrons? 29 1s2s2p3s3p 4s3d

29. Electron Configuration Notation Oxygen (8 e - ) Sulfur (16 e - ) Vanadium (23 e - ) 1s 2s2p 224 1s 2s2p 226 3s3p 24 1s 2s2p 226 3s3p 26 4s 2 3d 3

30. Rule: start from previous noble gas, then write the configuration Oxygen Sulfur Vanadium Noble Gas Notation [He] 2s2p 24 [Ne] 3s3p 24 [Ar] 4s3d 23

31. Valence Electrons Electrons in outer most energy level - located in highest s & p orbitals N: Mg: Se: 2s2p 23 1s 2 5 valence e - 2s2p 26 1s 2 3s 2 2 valence e - 2s2p 26 1s 2 3p4s 62 3s 2 3d4p 104 6 valence e -

32. Electron Dot Structure Shows valence electrons in a diagram Nitrogen (5 v.e.) Magnesium (2 v.e.) Selenium (6 v.e.) N Mg Se