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Unformatted text preview: ENSC 3313, Fall 2000 Name '- t,- "",,",,,i. " Answer alll O Questions. 2 Doints each. The Stasi (The E. Germany secret police) used to surreptitiously spray dissidents with radioactive scandium 46 (half life 84 days) and track them with Geiger counters to see whom they met. The doses could be up to 500 mSv; the "safe" limit was 1 mSv per week. (Ref. New Scientist, Ian. 6, 2001) How long would it take the radioactive scandium to decay by a factor of 500? A = 121 1-= e-t/121 Repeating 500 = ill days 2 State the likely electronic shell configuration for scandium, element 21 1s2 2s2 2p6 3s2 3p6 3dl 4s2 ~ the superscripts sum to 21. 3. In this course, we are very much concerned with the relationship between structure and'QroQerties. Use the element carbon to illustrate this theme. GRAPmTE DIAMOND Carbon occurs as diamond which is ~ and graphite which is hexagonal. They have totally different properties; for example, diamond is the hardest substance known and graphite is soft and friable -it...
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- Fall '11
- Atom, likely electronic shell, heavy FCC metal, lOO grams total