The Periodic Table

1. The Periodic Table

2. Periodic Table Dmitri Mendeleev (1834-1907) "We could live at the present day without a Plato, but a double number of Newtons is required to discover the secrets of nature, and to bring life into harmony with the laws of nature."

3. Modern Periodic Table

4. 1s 2s 2p n = 1 n = 2 n = 2 l = 0 l = 0 l = 0 ml = 0 ml = 0 ml = -1 ml = 0 ml = 1 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals H: 1s1

5. 1s 2s 2p n = 1 n = 2 n = 2 l = 0 l = 0 l = 0 ml = 0 ml = 0 ml = -1 ml = 0 ml = 1 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals He: 1s2

6. 1s 2s 2p n = 1 n = 2 n = 2 l = 0 l = 0 l = 0 ml = 0 ml = 0 ml = -1 ml = 0 ml = 1 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals Li: 1s2 2s1

7. 1s 2s 2p n = 1 n = 2 n = 2 l = 0 l = 0 l = 0 ml = 0 ml = 0 ml = -1 ml = 0 ml = 1 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals Be: 1s2 2s2

8. 1s 2s 2p B: 1s2 2s22p1 ‘core’ closed shell open shell: valence electrons s- and p-orbitals ‘Aufbau’ Principle: filling orbitals

9. 1s 2s 2p C: 1s2 2s22p2 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals Hund’s rule: maximum number of unpaired electrons is the lowest energy arrangement.

10. 1s 2s 2p N: 1s2 2s22p3 O: 1s2 2s22p4 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals

11. 1s 2s 2p F: 1s2 2s22p5 Ne: 1s2 2s22p6 s- and p-orbitals ‘Aufbau’ Principle: filling orbitals

12. s- and p-orbitals ‘Aufbau’ Principle: filling orbitals Na: 1s22s22p63s1 or [Ne]3s1 P: [Ne]3s23p3 Ar: [Ne]3s23p6 Mg: 1s22s22p63s2 or [Ne]3s2

13. d-orbitals 3d 4s 3p 3s 2p E 2s 1s Due to deeper penetration of s-orbitals, 4s lies lower in energy than 3d

14. d-orbitals K: 1s22s22p63s23p64s1 or [Ar]4s1 Co: [Ar]4s23d7 Ca: [Ar]4s2 Cu: [Ar]4s13d10 Sc: [Ar]4s23d1 Zn: [Ar]4s23d10 V: [Ar]4s23d3 Ga: [Ar]4s23d104p1 Cr: [Ar]4s13d5 Kr: [Ar]4s23d104p6

15. ‘s’-groups ‘p’-groups Beyond the d-orbitals d-transition elements lanthanides actinides f-transition elements

16. Aufbau rules 1. Within a shell (n) the filling order is s>p>d>f 2. Within a subshell (l), lowest energy arrangement has the highest number of unpaired spin (Hund’s rule) 3. The (n+1)s orbitals always fill before the nd orbitals 4. After lanthanum ([Xe]6s25d1), the 4f orbitals are filled 5. After actinium ([Rn]7s26d1), the 5f orbitals are filled Filled subshells accommodate: s: 2 electrons d: 10 electrons p: 6 electrons f: 14 electrons

17. Electron configuration Give the electron configuration of Zirconium and Tellurium. Identify the period and the group of the element Zirconium is in period 5 and is the 2nd element in the d-transition element group. Zr: 1s22s22p63s23p64s23d104p65s24d2 or [Kr]5s24d2 Tellurium is in period 5 and is the 4th element in the ‘p’- group. Te: 1s22s22p63s23p64s23d104p65s24d105p4 or [Kr]5s24d105p4

18. 92 93 94 uranium Ur Np Pu neptunium plutonium Exotic elements Elements with atomic numbers higher than 92 (Uranium) typically don’t exist in nature and have to be made by nuclear synthesis The first synthesized elements were named after the planets:

19. Einsteinium 101 99 107 Md Es Bh Mendelevium Bohrium 110 Barbarium? Uun Exotic elements Lives for only 10 ms! No name yet!

20. Atomic Radius How big is an atom? The atomic radius r is usually determined from the distances between atoms in covalent bonds. Atomic radius decreases across a period from left to right due to increased effective nuclear charge Atomic radius increases down a group because of the larger sizes of the orbitals with higher quantum numbers.

21. Atomic Radius

22. Atomic Radius

23. Atomic Radius Covalent radius is much smaller than the anionic radius.

24. Arrange the following sets of ions in order of increasing size: Na+, Rb+, Li+ : Cl-, F-, I- : Atomic Radius Arrange the following sets of atoms in order of increasing size: Sr, Se, Ne : Ne(10) < Se(34) < Sr(38) Fe, P, O : O(8) < P(15) < Fe(26) Li+(3) < Na+(11) < Rb+(37) F-(9) < Cl-(17) < I-(53)

25. e- + X(g) X+(g) + e- S(g) S+(g) + e- I1 = 999.6 kJ/mol 1st ionization energy S+(g) S2+(g) + e- I2 = 2251 kJ/mol 2nd ionization energy S2+(g) S3+(g) + e- I3 = 3361 kJ/mol 3rd ionization energy Ionization Energy Ionization energy is the energy required to remove an electron from a gaseous atom or ion :

26. S(g) S+(g) + e- I1 = 999.6 kJ/mol 1st ionization energy S+(g) S2+(g) + e- I2 = 2251 kJ/mol 2nd ionization energy S2+(g) S3+(g) + e- I3 = 3361 kJ/mol 3rd ionization energy Ionization Energy S: 1s22s22p63s23p4 Which electrons are removed in successive ionizations? Electrons in the outer subshells take the least amount of energy to remove (valence electrons) It takes about 1•103 kJ/mol to remove successive electrons from the 3p shell of sulfur.

27. Al(g) Al+(g) + e- I1 = 580 kJ/mol 1st ionization energy Al+(g) Al2+(g) + e- I2 = 1815 kJ/mol 2nd ionization energy Al2+(g) Al3+(g) + e- I3 = 2750 kJ/mol Al3+(g) Al4+(g) + e- I4 = 11,600 kJ/mol 3rd ionization energy 4th ionization energy Ionization Energy Ionization energies of aluminum: Al: 1s22s22p63s23p1 1st electron: 3p valence electron 2nd electron: 3s valence electron 3rd electron: 3s valence electron core electrons take much more energy to remove 4th electron: 2p core electron!

28. Ionization Energy

29. Ionization Energy First ionization energies General trends: Ionization energy increases across the period from left to right. Ionization energy decreases going down a group

30. Ionization Energy A closer look….. B: 1s22s22p1 New subshell, electron is easier to remove. O: 1s22s22p4 First paired electron in 2p orbital: repulsion.

31. Li Na K Cs Understanding a group Atoms in a group have the same valence electron configuration and share many similarities in their chemistry. Group 1A: Alkali metals

32. Understanding a group Group 1A: Alkali metals Trends down the group reflect periodic changes in mass, volume and charge.

33. Periodic Table in Brief

34. Periodic Table Redux

35. Periodic Table Redux