1. C. Johannesson III. Periodic Trends Ch. 6 - The Periodic Table

2. C. Johannesson A. Periodic Law When elements are arranged in order of increasing atomic #, elements with similar properties appear at regular intervals.

3. C. Johannesson B. Chemical Reactivity Families/Groups –Similar valence e - within a group result in similar chemical properties

4. C. Johannesson B. Chemical Reactivity Alkali Metals Alkaline Earth Metals Transition Metals Halogens Noble Gases

5. C. Johannesson C. Valence Electrons and Dot Diagrams Valence electrons: electrons in outermost energy level –Group number for the representative elements Don’t do transition elements Dot diagrams –Use dots to represent valence electrons Write symbol Start a dot at the top and go clockwise around –Then make pairs up to a maximum of 8

6. C. Johannesson Atomic Radius –size of atom © 1998 LOGAL First Ionization Energy –Energy required to remove one e - from a neutral atom. © 1998 LOGAL Melting/Boiling Point D. Other Properties

7. C. Johannesson Atomic Radius E. Atomic Radius Li Ar Ne K Na

8. C. Johannesson Atomic Radius –Increases to the LEFT and DOWN E. Atomic Radius

9. C. Johannesson Why larger going down? –Higher energy levels have larger orbitals Each row in the p.t. is called a period –Shielding - core e - block the attraction between the nucleus and the valence e - Why smaller to the right? –Increased nuclear charge without additional shielding pulls e - in tighter E. Atomic Radius

10. C. Johannesson First Ionization Energy F. Ionization Energy K Na Li Ar Ne He

11. C. Johannesson First Ionization Energy –Increases UP and to the RIGHT F. Ionization Energy

12. C. Johannesson Why opposite of atomic radius? –In small atoms, e - are close to the nucleus where the attraction is stronger Why small jumps within each group? –Stable e - configurations don’t want to lose e - F. Ionization Energy

13. C. Johannesson Successive Ionization Energies –Mg1st I.E.736 kJ 2nd I.E.1,445 kJ Core e - 3rd I.E.7,730 kJ –Large jump in I.E. occurs when a CORE e - is removed. F. Ionization Energy

14. C. Johannesson –Al1st I.E.577 kJ 2nd I.E.1,815 kJ 3rd I.E.2,740 kJ Core e - 4th I.E.11,600 kJ Successive Ionization Energies –Large jump in I.E. occurs when a CORE e - is removed. F. Ionization Energy

15. C. Johannesson G. Electronegativity the relative ability of its atoms to attract electrons in a chemical bond. –values are calculated and have a value of 3.98 or less. (see page 169) yIncreases across yDecreases down

16. C. Johannesson Decreases down a group –Shielding of core electrons Increases left to right across a period –Metals tend to lose e-; nonmetals gain G. Electronegativity

17. C. Johannesson F is most electronegative element (most attractive) Fr is the least electronegative (least attractive) G. Electronegativity

18. C. Johannesson Melting/Boiling Point –Highest in the middle of a period. H. Melting/Boiling Point

19. C. Johannesson Ionic Radius –Cations (+) lose e - smaller © 2002 Prentice-Hall, Inc. –Anions (–) gain e - larger I. Ionic Radius

20. C. Johannesson Which atom has the larger radius? –Be orBa –Ca orBr Examples

21. C. Johannesson Which atom has the higher 1st I.E.? –NorBi –Be orNe Examples

22. C. Johannesson Which atom has the higher melting/boiling point? –LiorC –CrorKr Examples

23. C. Johannesson Which particle has the larger radius? –SorS 2- –AlorAl 3+ Examples