Topic: The Periodic Table Aim: What trends exist on the Periodic Table?

1. Topic: The Periodic TableAim: What trends exist on the Periodic Table? Do Now: An unknown element is tested and is found to be ductile, malleable, and a good conductor. How would you classify this element? (metal, nonmetal, or metalloid)? HW:

3. Period • Horizontal row – there are 7 • Each period corresponds to adding another PEL! Period

4. Trends in a Period(as you go across ) • Atomic # increases • See Periodic Table • # of valence e- increases as # of p+ (atomic #) increases. Therefore, the valence shell is filling up! THE ELEMENT IS BECOMING CLOSER TO ACHIEVING STABILITY • See Periodic Table

5. Periodic Trends, cont. • Atomic radius decreases b/c there are more p+ in the nucleus (more + charges) which pull in the e- more • See Table S • Elements across a period have the same # of PELs • Ex. Period 4, 4 PELS, Period 2, 2 PELs • How do you know? CHECK THE e- CONFIG

6. Periodic Trends, cont. • Ionization energy generally increases • See Table S • Ionization energy – amount of energy needed to remove an electron. • This means that the atom is holding onto its e- more & more  why? • B/c the valence PEL is getting closer to CAPACITY (8)  they don’t want to let their e- go • Think – if you’re collecting something and your set is almost complete, you don’t want to let the pieces go! Conversely, if you’re just starting your collection, you might not be as sad to see them go.

7. Periodic Trends, cont. • Electronegativity generally increases • Electronegativity – how much an atom ♥s e- • ↑ eneg, >♥ for e- • Want to hold on to e- more & more as you move across the period • ↓ eneg, < ♥ for e-

8. Periodic Trends, cont. • Change from + to – oxidation states • + oxidation state = easier to LOSE an e- to form a + ion • - oxidation state = easier to GAIN an e- to form a - ion

9. Topic: Periodic Table • Aim: What are the trends in groups on the Periodic Table? • Do Now: Take out HW • As you go ACROSS a period, why does the ionization energy increase? • HW:REVIEW BOOK. TOMORROW. • PM review today for retakes. 3:00.

10. Group • Vertical column – there are 18 • Each group corresponds to adding another valence electron Group

11. Trends in a Group(as you go down ↓) • Atomic # increases • See Periodic Table • # of valence e- is the same – so ELEMENTS IN THE SAME GROUP HAVE SIMILAR CHEMICAL PROPERTIES • See Periodic Table

12. Group Trends, cont. • Atomic radius increases b/c a PEL is added each time you move downward • See Table S • Metallic character increases

13. Group Trends, cont. • Ionization energy generally decreases • See Table S • b/c the valence e- are farther away • They are easier to lose • Electronegativity generally decreases • Again, b/c the e- are farther away

14. Group Trends, cont. • Same oxidation states • Members of the same group have similar chemical & physical properties • They do chemistry similarly b/c they have the same # of valence e-

15. Sample Questions