Periodic Commonalities: halogens

1. Periodic Commonalities: halogens MP and BP very different X p mass MP (OC) BP ( O C) So what’s common ??? 3 7 11 23 19 40 37 85 55 133 -220 -101 -7 114 302 -188 -35 59 184 337 • Halogen chemistry !!! • 2Na + X2  2NaX (high melting white salts) • X2(colored) + ethene colorless dihalides • Breathing X2 kills you

2. Another example of periodic commonality inert (noble) gases p mass MP(o C) BP (0 C ) -272 - 269 -249 -246 -189 -186 -157 -152 -112 -107 -71 -62 • 4 • 20 • 40 • 84 • 131 • 86 222 So what’s common ??? Noble gas chemistry NONE

3. A final example of `period commonality’: reactivities of alkali metals Alkali metals SO WHAT’S COMMON ?? It’s all about …. [inert gas]ns1 chemistry SIZE (n) MATTERS !

4. Geography of Periodic Table see also figures on pp. 89,97 Main group elements Alkaline earth metals Noble metals Ag, Au, Pt (Cu) Noble gases halogens Transition metals Lanthanides (good to know too) f electrons here Alkali metals Actinides (good to know too) more f electrons here Know where metals, metalloids and non metalsare + stuff in yellow boxes

5. In-Class Drill/Practice

6. Periodic Table Geography Bee 1) Last column to right; Neon is an example Noble (Inert) Gases 2) Three main divisions: Metals, Non-Metals and….. Metalloids 3) Name two (2) of the metalloids B, Si, Ge, As,Te (Tellurium), Sb (Antimony), At (Astatine)…B,As,Ge,Si = microelectronic chips

7. Periodic Table Geography Bee (continued) 4) Chlorine is in this column Halogens 5) Another name for where d electrons live…. Transition metal block 6) Au, Pt, Ag, Cu…we’re special and called… NOBLE METALS (very unreactive…but not as unreactive as NOBLE GASES)

8. Periodic Table Geography Bee (continued) 7) Column 1 type elements are… Alkali Metals 8) Another name for where f electrons live…. Lanthanide or actinide 9) Au, Pt, Ag, Cu…we’re special and called… NOBLE METALS (very unreactive…but not as unreactive as NOBLE GASES)

9. Periodic Table Geography Bee (continued) 10) Calcium’s in this club. So is Barium and Radium. You can often dig us up…. Alkaline Earths 11) Another name for where p electrons live….and chemical act `normal’ Main Group Elements 12) The majority of elements are…. metals

10. Elements in the `hood’: 1) My atomic number is 17. What are two names for where I live ??? Halogens or Main Group element 2) My average atomic mass is ~73. Who am I and what kind of animal am I ??? Germanium (Ge), a Metalloid 3) [Ar] 3d104s1 (when I’m `right’). Who am I and am I metal, metalloid or non-metal Copper (Cu) a metal

11. Elements in the `hood’ (continued): 4) Since we’re here, name two different names for where Cu lives Transition metal block and noble metal 5) I’m in table salt, colored green as a gas and am sweet 17…I must live where ? (name the column) Chlorine…in the halogen column 6) I ‘m very rightwing, lazy, and never mix with lower class elements.I weigh ~40. Who am I and what sort of animal am I Argon an inert=noble gas

12. Exam 1 Headers and sample questions (Monday 23 September 2013) • 1.0. Introductions (3 pts) • What corporation did Doc Fong work at before becoming an impoverished chemistry professor? • __________________________________ • 1.1 Atomic dimensions and scaling (6 pts) • What is the ~ratio of an electron orbit diameter to an atomic nucleus diameter?____________________ • What is the ratio of proton to electron mass ? ___________ • If baseball (~2 inches across) is the nucleus the electrons would be • a) 10 feet away b) 300 miles away c) 3 miles away

13. 1.2 Element Symbols and Names (18 pts) • Circle all the symbolic representations of atomic elements below that are incorrect: (must circle all for credit) • BB XetOyyy Cr • Write the correct name or symbol for the elements listed below: (1 pt for each correct answer) SPELLING MATTERS • Silver ____ Hg _________ potassium ___ • How many neutrons are present in neutral Boron-11 ? __

14. 1.4 Evolution of the Atomic Model ( 10 pts) 1.3 Atomic Body Part Count (8 pts) 1.4. Evolution of the Atomic Model (10 pts) a)Whose atomic model is this ? b)Which model doesn’t rely on theory at all ?

15. 1.5. Wave and Planck’s Laws Calculations ( 9 pts) Given that *f = c=3*108 m/s Calculate f given =10,000 m ____ Given E=hf= hc/ ; h=6.63*10-34 J*s c=3*108 m/s Calculate E given f=3*107hz _______________ Calculate E given  =1*10-4 m _______________ 1.6. Bohr’s Theory of the atom (4 pts) Name two failures of the Bohr theory of the atom:: 1) 2)

16. 1.7. Electronic Configurations of the Atoms (using the Periodic Table provided during exam) 22 pts Write the complete electronic configurations for the elements below Mg _________________________________ Write the correct abbreviated electronic configurations for the elements below, making sure to pay attention to all the rules associated with d electrons if they are present. P_______ Fe__________ Write the correct pigeonhole (orbital) diagrams for the elements below, making sure to pay attention to all the rules associated with d electrons if they are present, and including the correct inert gas core. Cr_________________ Cu__________________________

17. 1.8 Periodic Table Predictions and Vocabulary (12 pts) • See mini-quiz 10 • Chlorine is in this group column __________________ • Example of an alkali metal__________________ • 1.9 This, that and the other things (7 pts) • What experiment destroyed the old theory of light ? _____________________________ • True or False • Bohr’s theory of the atom is good for all the elements. T F

18. Periodic Trends in Selected* Physical Properties of the Elements (see pp. 91-98) Trend=> across a row Trend=> down a column *The usual suspects varied… • Covalent Atomic Radii, r • First Ionization Potentials, I1 • Electron Affinities, EA

19. Covalent atomic radius, r, defined 2r Atoms of element are assumed to be spherical and `covalently’ bonded (no net charge on either atom) see also: p. 95, figure 2.35

20. First Ionization Potential, I1 defined (see also p.91) I1 is the energy required to remove the first electron from an initially neutral element X (The electron ejected is the easiest one to eject) I1+ X  X+ + e- Example: I1+ Li Li+ + e- I1 in 2s 1s

21. Electron Affinity, Eadefined (see p. 94) Me want to bond with Li  !! Eais the energy released when an electron is added to an initially neutral element X. (Because the system is losing energy, Ea is < 0) e-+ X  X- + Ea Eaout Example: e- + Li Li- 2s 1s

22. The estimated r for most of the elements (crystallographic data)

23. What’s the trend for r across a row ? ? Trend down a column ? r decreasing… r ~increasing except…

24. Size decrease across a row reveals that not all electrons are created equal… Ability of given electron type to neutralize (shield off) its nuclear proton follows the order: s> p > d > f The weaker the neutralization (shielding), the more powerful is the pull of the un-neutralized protons…which then pull the entire electron cloud closer in. (see p. 95)

25. The increase down a column compares the sizes of the same kind of orbital electrons…except that as we go down the column, the number of electrons increases. Hence, size should increase. H 1s Li [He] 2s Na [Ne] 3s K [Ar] 4s Rb [Kr] 5s Cs [Xe] 6s 1 e- 3 e- 11 e- 19 e- 37 e- 55 e- Example: column 1- the alkali metals

26. U-Do-It Predictions… If you understand the reason for the trend in r, you can predict the trends in Ionization potential, I1and Electron Affinity, Ea I1 trends ?? …and why I1increases across..because protons pull harder on electrons, making them harder to remove I1decreases down..because electrons are further away As we move down making them easier to remove ?? ??

27. U-Do-It Predictions… If you understand the reason for the trend in r, you can predict the trends in Ionization potential, I1and Electron Affinity, Ea Eatrends ?? …and why Eaincreases across..because protons pull harder on new electrons, which means a deeper potential well Eadecreases down..because open orbits are further away as we move down making them more shallow in potential ?? ??