1. Question of the Day Elements on the right side of the periodic table form _________ ions Elements in the same group form ___________ ions negative The same Day 2 1-27

3. Octet rule – notes page 6 Octet rule – Atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons (8)

4. What is electronegativity? How does it increase on the p. t. ? Electronegativity – ability to attract electrons in a bond

5. How does it increase on the p. t. ? In this bond: Ba—S, which way do elecs. Shift? WHY? S, > electroneg.

6. Periodic Trends Ionization energy – energy needed to remove one electron from an atom Li → Li + + e - … indication of how strongly an atom holds onto its outermost elecs.

7. Periodic Trends The graph on page 178 shows how ionization energies vary with atomic # What element does the black point at (10, 2100) represent? With respect to the periodic table ionization energies show 2 important trends…

8. Periodic Trends With respect to the periodic table ionization energies show 2 important trends… 1. Decrease as you move down a group 2. Increase as you move left to right across a period

9. Periodic Trends How does the ionization energy trend compare to the atomic radius trend? Does this make sense?

10. Periodic Trends O Be Cl ----- - What’s bigger:↑er I. E.: O or C Be or Ca Na or Be Cl of Al Ca or B +3 IN NOTES

11. Periodic Trends O Mg Be Cl ----- - What’s bigger:↑er I. E.: O or B Mg or Sr K or Be Cl of Si Sr or Al +3 IN NOTES

12. Periodic Trends Successive Ionization energies (removing more than one electron from an atom): - The 2 nd > 1 st, the 3 rd > 2 nd, the 4 th > the 3 rd - but if you look at the I. E. s there is usually a large jump. Where? PAGE 178

13. Add the following trends: Reactivity Size (atomic radius) Electronegativity

14. Assignments Online assignment = shssci.wikispaces.com Read section 6.3 and complete #s 18, 19, 21, 22, 24, 25 on page 182 BOTH DUE BY THE END OF THE PERIOD!!!

15. Periodic Trends How does atomic radius change? Why? How does ionization energy change? Why?

16. Ionization energy Fluorine Noble gas Inert Group 17 Malleable Ductile Alkali metals Francium Period 4 Electronegativity Octet Rule Double periods

18. C B A

19. Atomic mass *** _________ *** _______ Similar properties: _______________ __________________ (groups) Families