Pu Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery­gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. It is radioactive and can accumulate in the bones; handling of plutonium dangerous. Plutonium is the heaviest primordial element by virtue of its most stable isotope, plutonium­244, whose half­life of about 80 million years is just long enough for the element to be found in trace quantities in nature. Plutonium is mostly a byproduct of nuclear reactions in reactors where some of the neutrons released by the fission process convert uranium­238 nuclei into plutonium. Plutonium­238 has a half­life of 88 years and emits alpha particles. It is a heat source in radioisotope thermoelectric generators, which are used to power some spacecraft. Plutonium isotopes are expensive and inconvenient to separate, so particular isotopes are usually manufactured in specialized reactors. How long will it take for a 134 gram sample of of Pu­238 to decay into a 23 gram sample? 1 Chemistry 1. Warm­Up ­5 2. Review POGIL Activity/Homework ­20 3. Lewis Dot Structure/VSEPR Notes ­20 4. VSEPR POGIL/Building Compounds ­45 Announcements Due Today: Finish POGIL Activity and Read Pages 298 to 308 and answer questions 57, 59, 61­62, 69, 71, 73, and 81. Due Tuesday June 10th: Mole Airlines Extra Credit Due Tuesday June 10th: Read pages 317 to 331 and answer questions 1 ­ 9 odd, 15, 17, 19 and 25. Begin work on Study Guide! ­ Will be available after school today. Unit 5 Test out of 45 instead of 46 (Question 5 is extra credit now) 2 Figure 10.22/23 3 4 2 more things to note: 1.As the quantum number increases 2. Pauli Exclusion Principal 5 6 Electron Configuration Notes Diagram keywords a. electron configuration b. orbital diagram c. valence electron d. core electron 7 Electron Configuration Notes Practice Problems Write the electron configuration for the following: 1. H 2. He 3. C 4. F 5. Ca How many electrons can fit into the first principal quantum level? How many electrons can fit into the second principal quantum level? How many electrons can fit into the third principal quantum level? Derive an equation that relates quantum level to number of electrons. 8 Electron Configuration Notes Periodic Table 1. 3 Types of elements a. metals b. nonmetals c. metaloids d. Representative Elements 2. Periodic Table Trends a. Ionization Energy b. Electronegativity c. Atomic Size 9 Bonding Notes ­ Chapter 11 Definitions a. Bond­ b. Bond energy­ c. Ionic bonding d. ionic bonding e. covalent bonding i. non­polar covalent bonding ii. polar covalent bonding 10 f. electronegativity For each of the following compounds, choose the bond that will be more polar. a. H­P or H­C b. H­S or H­F g. dipole moment 11 Lewis structures In almost all stable chemical compounds of the representative elements, all of the atoms have achieved a noble gas electron configuration. Lewis structure: Octet rule: Lone pairs: Examples of Lewis structures 1. H2O 2. NH3 3. CO2 12 VSEPR Model Steps for predicting Molecular Structure Using the VSEPR Model 1. 2. 3. 4. Example 13 POGIL Activity with Modeling Kits! 14 Exit Question What does VSEPR stand for? Reminder(s) Due Tuesday June 10th: Mole Airlines Extra Credit Due Tuesday June 10th: Read pages 317 to 331 and answer questions 1 ­ 9 odd, 15, 17, 19 and 25. Begin work on Study Guide! ­ Will be available after school today. 15.