4. Are there any exceptions to these trends? If so, which elements break the trend? Why did you arrange these elements the way you did? 5. Are there any holes or gaps in your arrangement? Where are they? What do you think these gaps might mean? 6. Is there a repeatable pattern that might allow you to predict the properties of “undiscovered” elements? Part 2 Here is a quote by Friedrich Beilstein, a colleague of Mendeleev (who didn’t like the Russian very much): . . . has prophesied the existence of all sorts of new elements and believes “Mendeleev that he needs only to conceive of them in order to have them immediately in the bag. . . . He is in general an odd chap.” (This was a tremendous insult back in the day) Perhaps Mendeleev came back with (pere iti k’dyavoloo)! Or more informally Перейти к дьяволу (k’chortu)! К Чорту However, such evidence came in 1875. The French chemist Paul-Emile Lecoq de Boisbaudran discovered a new element he named gallium. Later, in 1886 a German chemist named Clemens Winkler discovered an element he called germanium. Obtain the second set of cards and see where they fit into your table. Be able to defend your decision. Record your decision in your lab notebook. Add these new elements to your diagram. Part 3 Obtain the third set of cards and determine where they should fit into your table. Be able to defend your position. Record your decision in your lab notebook. Add these new elements to your diagram. Part 3 Analysis Questions 1. After you prepared your periodic tables, you received additional sets of cards to fit into your tables. How did your table change each time you added new elements to your table? 2. How is your table similar to a modern periodic table? How is yours different? 3. How do we explain today the fact that tellurium comes before iodine in the periodic table, even though tellurium has a higher atomic mass than iodine? 4. Mendeleev predicted the existence of gallium and germanium because of the holes in his periodic table. Why do you think Mendeleev did not predict the existence of the noble
4. Are there any exceptions to these trends? If so, which elements break the trend? Why did you arrange these elements the way you did? 5. Are there any holes or gaps in your arrangement? Where are they? What do you think these gaps might mean? 6. Is there a repeatable pattern that might allow you to predict the properties of “undiscovered” elements? Part 2 Here is a quote by Friedrich Beilstein, a colleague of Mendeleev (who didn’t like the Russian very much): “Mendeleev . . . has prophesied the existence of all sorts of new elements and believes that he needs only to conceive of them in order to have them immediately in the bag. . . . He is in general an odd chap.” (This was a tremendous insult back in the day) Perhaps Mendeleev came back with Перейти к дьяволу (pere iti k’dyavoloo)! Or more informally К Чорту (k’chortu)! However, such evidence came in 1875. The French chemist Paul-Emile Lecoq de Boisbaudran discovered a new element he named gallium. Later, in 1886 a German chemist named Clemens Winkler discovered an element he called germanium. Obtain the second set of cards and see where they fit into your table. Be able to defend your decision. Record your decision in your lab notebook. Add these new elements to your diagram. Part 3 Obtain the third set of cards and determine where they should fit into your table. Be able to defend your position. Record your decision in your lab notebook. Add these new elements to your diagram. Part 3 Analysis Questions 1. After you prepared your periodic tables, you received additional sets of cards to fit into your tables. How did your table change each time you added new elements to your table? 2. How is your table similar to a modern periodic table? How is yours different? 3. How do we explain today the fact that tellurium comes before iodine in the periodic table, even though tellurium has a higher atomic mass than iodine? 4. Mendeleev predicted the existence of gallium and germanium because of the holes in his periodic table. Why do you think Mendeleev did not predict the existence of the noble
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