1. C HAPTER 7: P ERIODIC P ROPERTIES OF THE E LEMENTS Exploration of important properties of elements across a row or down a column.

2. J ANUARY 2 ND, 2013 Do Now: Take out your homework, compare your answers to a neighbor.

3. F ROM M ENDELEEV TO M OSELEY 1869: Mendeleev arranged elements by atomic mass Noted similarities, forced to leave holes in PT 1913: Moseley Developed concept of atomic numbers Bomabrded elements with high-energy electrons Unique frequency Correctly identified atomic number as number of protons

4. E FFECTIVE NUCLEAR CHARGE Where do many of the properties of atoms originate? How does Coulomb’s law relate to effective nuclear charge? As we get further from the nucleus, how is our effective nuclear charge effected?

5. E FFECTIVE NUCLEAR CHARGE CONT. Why is analyzing the effective nuclear charge precisely problematic? How do we estimate these interactions?

6. E FFECTIVE NUCLEAR CHARGE Z eff = Z − S where: Z = atomic number S = a screening constant (usually close to the number of inner electrons)

7. T RENDING How does effective nuclear charge change across a period? Why? How does effective nuclear charge change down a period?

8. Van der Waals Radius (Non-bonding radius) : is the radius of an atom when it is bonded to another atom by van der Waals forces. Covalent atomic radius(Bonding radius): is half the distance between two atoms covalently bonded.

9. A TOM S IZE Had students read 7.4 in the textbook and then had class discussion

10. J ANUARY 3 RD, 2012 Do Now: In terms of effective nuclear charge, explain the atomic radius trend both across a period and down a group. Arrange the following isoelectronic series in decreasing atomic size: K +, Cl -, Ca 2+, S 2-

11. A RE YOU A BRAINIAC ?

12. I ONIZATION E NERGY Define Ionization Energy. How do we differentiate between 1 st and 2 nd ionization energies? How is the difficulty of removing an electron correlated with ionization energy?

13. T RENDING ! I 1 < I 2 < I 3, Why? How is the ionization energy affected w/ removal of electrons from an inner shell? Page 259 (table)

14. T RENDING C ONT. How does ionization energy trend from left to right across a period? How about down a group? Generally, s + p block show larger range in values for ionization energy. The d block increases minimally. The f, very little.

15. P RACTICE Which has a higher third ionization energy, Ca or S? Why? Why does Boron have a lower ionization energy than Beryllium? Why is it easier to remove a 2p electron from oxygen than from nitrogen?

16. J ANUARY 4 TH, 2012 DO NOW : Arrange the following atoms in order of increasing ionization energy: Neon, Sodium, Phosphorus, Argon, and Potassium. Arrange the following atoms in order of decreasing ionization energy: Boron, Aluminum, Carbon, and Silicon

17. S O HOW DOES IONIZATION WORK ? When electrons are removed from an atom, they are removed from occupied orbital with highest principle quantum number. IE: Lithium. Try removing 2 electrons from Iron. How about a third? Try removing 2 electrons from Tin. How about 4?

18. P RACTICE Write the electron configurations for the following: Ga 3+ Cr 3+ Br -

19. A WKWARD ? Why is using ionization energy “awkward” when talking about forming an anion? Instead, we use the term “electron affinity”! Energy is released when adding an electron. How would we represent this numerically?

20. H OW DOES THIS ALL TIE TOGETHER ? How can we differentiate between ionization energy and electron affinity? What does the electron affinity of a noble gas look like?

21. P REDICTIONS ! Predict which group would have the most negative electron affinities. Why? What is the relationship between the value of the first ionization energy of Cl - (g) and the electron affinity of Cl(g)?

22. B ROADLY SPEAKING … Elements organized as metals, nonmetals, metalloids. Metals: Luster; various colors although mostly silver Solids malleable and ductile Good conductors Most metal oxides are solids that are basic Tend to form cations in aqueous solution Non Metals: No luster, various colors Solids usually brittle; some hard, some soft. Poor conductors Most nonmetal oxides are molecular substances that form acid solutions Tend to form anions in aqueous solution

23. M ETALLIC C HARACTER Where is the “most” metallic metal located on the periodic table? What is the general trend for metallic character based on this information?

24. M ETALS Which metals is a liquid at room temperature? How can we use first ionization energy to characterize metals vs. nonmetals? Why are most metal oxides basic?

25. M ETAL OXIDES Most metal oxides are basic. Metal Oxides + Water  Metal Hydroxide IE: Na 2 O (s) + H 2 O (l)  2 NaOH (aq) Due to oxide ion, which reacts with water. IE: O 2- (aq) + H 2 O (l)  2 OH - (aq) Insoluble metal oxides react with acids to form salt plus water. IE: NiO (s) + 2 HNO 3 (aq)  Ni(NO 3 ) 2 (aq) + H 2 O (l)

26. P RACTICE Would you expect scandium oxide to be a solid, liquid, or gas at room temperature? Write the balanced chemical equation for the reaction of scandium oxide with nitric acid. Write the balanced chemical equation for the reaction between copper (II) oxide and sulfuric acid.

27. N ON METALS How can non-metals exist at room temperature? Why are most non-metal oxides acidic? Nonmetal oxide + water  acid Most nonmetal oxides dissolve in basic solutions to form salt and water.

28. P RACTICE Write the balanced chemical equation for the reaction of solid selenium dioxide with the following: Water Aqueous sodium hydroxide Write the balanced chemical equation for the reaction of solid tetraphosphorus hexoxide with water.