1. The Electronic structure of an atom

2. Bohr’s model of an Atom Electrons located in circular orbits around an atom When an electron absorbs or emits energy it moves from 1 orbit to the next The greater the energy the farther from the nucleus

3. Energy level: a specific amount of energy which an electron in an atom can possess

5. When an electron is hit with energy it can jump to another energy level

7. As an electron in a higher energy level gives off energy (light) it drops down to a lower level

8. Quantum: The energy difference between two particular energy levels Orbital: the actual region of space occupied by an electron at a specific energy level

9. Energy levels are designated by a quantum number called “n – the principal quantum number” Level n=1 has just the 1s orbital

10. Shape representation for a 1s orbital - 2 electrons can occupy the 1s orbital. - Start in energy level n = 1.

11. The n=2 level has 4 orbitals, a 2s (same shape but larger than a 1s) and three 2p orbitals n = 1 n = 2 n = 3 n = 4 1s 2s 3s 4s 2p 3p 4p 3d 4d 4f Energy Level Diagram for Hydrogen

12. p orbitals 3 orbitals in total. 2 electrons can occupy each orbital. All 3 orbitals can be in one orbital level (n level). Start in energy level n = 2.

14. N=3 level has one 3s, three 3p orbitals and five 3d orbitals. Each level “n” has n 2 orbitals n = 1 n = 2 n = 3 n = 4 1s 2s 3s 4s 2p 3p 4p 3d 4d 4f Energy Level Diagram for Hydrogen

15. d orbitals 2 electrons per orbital. Total of 5 orbitals. Total of 10 electrons. Start at energy level n = 3.

16. The five 3d orbitals

17. Level n = 4 has a 4s, three 4p orbitals, five 4d orbitals and seven 4f orbitals n = 1 n = 2 n = 3 n = 4 1s 2s 3s 4s 2p 3p 4p 3d 4d 4f Energy Level Diagram for Hydrogen

18. f orbitals: 2 electrons per orbital. Total of 7 orbitals. Total of 14 electrons. Start at energy level n = 4.

19. The 4f orbitals

20. Energy level diagram for polyelectron atoms. #’s = n. Letters = type orbitals. Dashed lines = orbitals = 2 electrons per dashed lines.

21. Shell: the set of all orbitals having the same n value. 3 rd shell has 3s, 3p, and 3d Subshell: a set of orbitals of the same type 5 3d orbitals in the 3 rd shell

22. Look at the diagram on p153 For a given value of “n”, n different types of orbitals are possible. For n = 1: only the s- orbital is possible. For n = 2: the s – and p- orbitals are possible. For n = 3: the s-, p-, and d- orbitals are possible. For n = 4: the s-, p-, d-, and f- orbitals are possible

23. An s- subshell consists of 1 s- orbital. A p – subshell consists of 3 p- orbitals. A d- subshell consists of 5 d- orbitals. An f- subshell consists of 7 f- orbitals.

24. s subshell = 2 electrons p subshell = 6 electrons d subshell = 10 electrons f subshell = 14 electrons

25. Electron configuration Rules: –Add to orbitals having lowest energy first –Max of 2 electrons per orbital

26. Electron configuration