Element of the Day ­ Rb Rubidium (roobideeәm) is a chemical element with the symbol Rb and atomic number 37. Rubidium is a soft, silverywhite metallic element of the alkali metal group. Its atomic mass is 85.4678. Elemental rubidium is highly reactive. Rubidium has only one stable isotope, 85Rb. German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed method of flame spectroscopy. Its compounds have chemical and electronic applications. Rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for laser manipulation of atoms. http://www.youtube.com/watch?v=FCz7424Vo0E Question: How many protons, neutrons, and electrons does 85Rb Have? 1 Chemistry 1. Element of the Day ­10 2. Review POGIL ­10 3. Notes ­30 4. Quiz ­20 5. More Notes ­10 6. Group Activity ­20 Announcements Due Today: Finish POGIL Activity and study for quiz! Quiz Tuesday! Due Thursday: Read pages 102 to 110 and answer questions 55 ­ 73 odd. 2 Review POGIL 3 VI. Periodic Table Introduction Parts/Trends in the table/Key terms 4 Average Atomic Mass • weighted average of all isotopes • on the Periodic Table • round to 2 decimal places 5 Atomic Mass Calculate the atomic mass of copper if copper has two isotopes. 69.1% has a mass of 62.93 amu and the rest has a mass of 64.93 amu. 6 Average Atomic Mass • EX: Calculate the avg. atomic mass of oxygen if its abundance in nature is 99.76% 16O, 0.04% 17O, and 0.20% 18O. Avg. Atomic Mass = 7 8 9 Your turn Assume you have only two atoms of chlorine. One atom has a mass of 35 amu (Cl‐35) The other atom has a mass of 36 amu (Cl‐36) What is the average mass of these two isotopes? Looking at the average atomic mass printed on the periodic table...approximately what percentage is Cl‐35 and Cl‐36? is a good approximation 10 Naming Isotopes Put the mass number after the name of the element ‐Examples • carbon‐ 12 • carbon ‐14 • uranium‐235 11 · Dmitri Mendeleev developed the modern periodic table. · Argued that element properties are periodic functions of their atomic weights. · We now know that element properties are periodic functions of their ATOMIC NUMBERS. 12 Periodic Table of the Elements I. Metals a. Alkali Metals b. Alkali Earth Metals c. Transition Metals II. Metaloids (semimetals) III. Nonmetals a. halogens b. noble gases 13 Periodic Table of the Elements III. Periods IV. Groups ­ 14 Carbon is a: a. alkali metal b. metaloid c. nonmetal d. transition metal 15 Which of the following would be dull, brittle, poor conductor of electricity: a. alkali metal b. metaloid c. nonmetal d. transition metal 16 Quiz 17 18 V. Periodic Table ­ Naming Ion A. Cations B. Anions Determine net ionic charge of a compound. 19 Period 1 Group 1 Devereaux, Christina Group 3 Brown, Rosemary E. Fabert, Emma M. Lee, Alyssa Sanford, Nicole L. Jameson, John Delgado, Malena A. Powell, Amber D. James, Alyssa L. Scott, Benjamin W. Millican, Greg Cowan, Eliana R. Group 2 Karreman, Anneke J. Group 4 Beatie, Natalie T. Williamson, Benjamin Ploger, Braden T. Sander, Cole R. Sellman, Megan R. Sharp, Peter S. Treskin, Kaylie J. Arlt, Kaitlyn C. Gordon, Laura Gori, Miles B. 20 Period 3 Group 1 Amelang, Russ H. Group 5 Callaham, Shawn E. Ginder, Caroline R. Eckert, Kathleen B. Friday, Angelic D. Minasian, Aria L. Schuelke, Ragsdale, Albert C. Maximilian Young, Ruth P. Hobbs, Robert M. Olson, Sonia K. Kulfan, Riley L. Bowman, Matthew Rabinowitz, Maiya Group 2 Group 4 D. R. Haines, Madeline Reynolds, Devon B. A. Strevell, Noah C. Alnwick, Ashley P. Wolgamott, Jackson, Jordan Melody A. Wiggins, Kaitlyn Al‐Kazily, Tarkan Gonwick, Dawson Philip, Samantha L. L. Group 3 Ieropoli, Ryan B. Jumpa, Aaron M. McCann, Cristen H. McCombs, Duncan N. Holt, Ryan A. 21 Exit Question: Arrange the following metals with increasing activity: a. Aluminum, Magnesium, Sodium b. Magnesium, Aluminum, Sodium c. Sodium, Aluminum, Magnesium d. Sodium, Magnesium, Aluminum Reminder(s): Read pages 102 to 110 and answer questions 55 ­ 73 odd. 22.