Chapter 8 The Periodic Table

1. Chapter 8The Periodic Table

2. What is the Periodic Table good for?

3. The Periodic Table Symbols and names Protons, electrons, & neutrons Atomic mass Size of atoms & ions Strength of ions (electronegativity) Electron configuration

4. Atomic Size • How is atomic size determined? • The electron cloud doesn’t have a definite edge.

5. Atomic Size } • Atomic Radius = half the distance between two nuclei of a diatomic molecule. Radius

6. Trends in Atomic Size Influenced by two factors: • Energy Level • Higher energy level is further away. • Charge on nucleus • More charge pulls electrons in closer.

7. Group trends H Increasing number of energy levels Li Na K Rb

8. Periodic Trends • As you go across a period the radius gets smaller. • Same energy level. • More nuclear charge. Na Mg Al Si P S Cl Ar

9. Ionic Size • Cations formed by losing electrons. • Metals form cations. • Cations of representative elements have noble gas configuration.

10. Ionic size • Anions form by gaining electrons. • Nonmetals form anions. • Anions of representative elements have noble gas configuration.

11. Group trends Increasing number of energy levels Li+1 Na+1 K+1 Rb+1 Cs+1

12. Periodic Trends Energy level changes between anions and cations. N-3 O-2 F-1 B+3 Li+1 C+4 Be+2

13. Electronegativity • The tendency for an atom to attract electrons to itself when it is in a compound

14. Group Trend • The further down a group, the farther the electron from the nucleus • More willing to share. • Lower electronegativity.

15. Periodic Trend Metals are at the left end • Metals lose electrons • Low electronegativity At the right end are the nonmetals. • Nonmetals gain electrons • High electronegativity.

16. Electron Configuration Atomic Orbitals fill up in a regular pattern. The outside orbital electron configuration repeats. Therefore, the properties of atoms repeat.

17. H 1 Li 3 Na 11 K 19 Rb 37 Cs 55 Fr 87 1s1 1s22s1 1s22s22p63s1 1s22s22p63s23p64s1 1s22s22p63s23p64s23d104p65s1 1s22s22p63s23p64s23d104p65s24d10 5p66s1 1s22s22p63s23p64s23d104p65s24d10 5p66s24f145d106p67s1

18. He 2 1s2 1s22s22p6 1s22s22p63s23p6 1s22s22p63s23p64s23d104p6 1s22s22p63s23p64s23d104p65s24d105p6 1s22s22p63s23p64s23d104p65s24d10 5p66s24f145d106p6 Ne 10 Ar 18 Kr 36 Xe 54 Rn 86

19. S- block s1 • Alkali metals all end in s1 • Alkaline earth metals all end in s2 • Helium included is S - block s2

20. Transition Metals -d block s1 d5 s1 d10 d1 d2 d3 d5 d6 d7 d8 d10

21. The P-block p1 p2 p6 p3 p4 p5

22. f6 f13 f1 f2 f3 f4 f5 f7 f8 f10 f12 f14 f11 f9 F - block • inner transition elements

23. 1 2 3 4 5 6 7 • Each row (or period) is the energy level for s and p orbitals.

24. D orbitals fill up after previous energy level 1 2 3 4 5 6 7 3d

25. 1 2 3 4 5 6 7 • f orbitals start filling at 4f 4f 5f

26. Writing Electron Configurations the Easy Way

27. Electron Configurations Repeat • As you move across a period, the outermost energy level is filled • This is the basis for writing shorthand electron configurations.

28. The Shorthand Aluminum 1s22s22p63s23p1 • Ne is 1s22s22p6 • so Al is [Ne] 3s23p1

29. The Shorthand Again Sn- 50 electrons The noble gas before it is Kr Takes care of 36 Next 5s2 Then 4d10 Finally 5p2 [ Kr ] 5s2 4d10 5p2