DOUGLAS D. SMITH Guilford High School Rockford. Illinois 61 11 1
Lecture Notes or Facts that are Hard to Work into a Conversation W (or a rose by any other name) ~h~ international union of pureand ~ ~ ~chemistrV l i ~ has decided t o designate .iqW as wolfram. T h e American delegation t o IUPAC has thus far refused to accept the change and will continue t o call it tungsten.
1925 JCE and New Elements 43 and 75 In matter-of-fact. short notes. this Journal in 1925 reported the discoveryof three new elements. Girman scientists named their two discoveries rhenium and masurian. for elements 7 5 and .!:I, respectively. 'I'hrst: nrr names dtrrritories that (iermany Ihsl >ISi~ result uf prate rreaties Innu \ V d d \Var .1. If masurian doesn't sound familiar, it shouldn't. Element 43 had heen given various names hy other scientists when they thought they had made its discovery. Names such as polinium, iljenium, peopium, davyum, lucium, nippinium, and moseleyum were all used until Perrier and Segre showed they had made the new element named technetium. Technetium is derived from a Greek word for "artificial" as it was the first
artifically produced element. Kenna has a more complete d history .of. the element appearing in an earlier issue of this Element 75 had heen given the names of hafnium and celtium in 1925 by two groups of claimants. T h e claims of Coster and Hevesy for hafnium were eventually accepted because thev were able to oroduce concentrated amounts and establish major features of its chemistry. T h e most interesting aspect of the element is that the discoverers claim-hat it was hy following the "theoretical deductions" of the quantum theory explained to them by Neils Rohr that they were ahle to make the discovery, thus giving support to the new theory. Hafnium is based on the Latin name for Copenhagen, Hafnia. As both Coster and Hevesy as well as Bohr were a t Copenhagen a t this time, it seems logical. Coster and HevesyYwrote, "This confirmation of the theory was the deciding factor in our choice of the name hafnium for the new element.''
.ITHEM.
'Kenna, R. T., EDUC., 39,438, (1962). Taster, D. and Hevesy, G., Nature, 111,252,(19231.
Practice in Thinking-Part Gone from the puhlishers' lists hut not forgotten is Jay A. Young's 1958 lab manual.' T h e two sections plus a third dealing with lah techniques, hristle with ideas that a t least stimulate thought, a t most a sudden desire to steal. For example, Young's approach to the problems students encounter when asked to observe a reaction, study (gasp) resource materials, and propose solid, testahle answers can he adapted to any level from neophyte freshmen to gung-ho Advanced Placement seniors. Here is a sampling from eight of the seventeen categories Dr. Young developed. G n w p A-Phys~col Changes 1) Put several small pieces of Dry Ice into a ruhber balloon. Tie the neck tightly with a small piece of string. Wait. Why did the balloon burst? 21 Wrap a small piece of filter paper around the bulh of a thermometer. Soak the filter paper with acetone; then blow gently on the filter paper. Why did the thermometer indicate a drop in temperature? 31 Put approximately 1 g of calcium chloride on a watch glass. Let
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it stand undisturbed for a few days. Why did liquid collect on the watch glass? Group R-Ions in Solution 4) In a test tube add 5 ml of 0.5 M CH:,COONa solutinn to 5 ml 01 0.5 M AgNO:, solution. Stir the mixture and note the color of the precipitate. Add 5 ml of 0.5M Nal solution; stopper the test tuhe and
shake it. Why did the precipitate change colcw? 5 ) Mix 5 ml of 0.1 M AgNO:, solution with 5 ml of 0.1 M HCI solution. Add 3 M NH40H solution, drop hy dmp, with stirring, until the precipitate just dissr,lves.Then add, stirring, 10 ml of 0.1 M HCI s a ~ lution. Add 5 ml of 0.15 M NazSsO:, solution. Stir. Why did the precipitate dissolve, reappear, and then dissolve again?
IDEAS is a bimonthly feature consisting of abstracts of articles and other items that high school teachers may find of immediate use in their clasxs. Comments and suggestions for Ideas are encuuraaed and may he sent directly to the column editor.
Volume 55,Number 1, January 1978 1 49
6 ) Mix 5 ml of 0.1 M (CH:ICOO)~ P h solution with 5 ml of 0.1 M NarSOI solution. Then add 5 mlof0.2 M KrCrOn solution. Stir. Why did the precipitate change color?
1;rrrup C-l'rrrprrli~s of Caws 7) Light a candle. Invert a small heaker and lhwcr it over the candle flame, holding it in this position for a few seconds. Why was the flame extinguished? 8) Open a lhclttle r,froncentrated hydrochloricacid. Wait. Why did t h e fumes issue fwm t h e open mouth o f t h e bottle? Group D-TI,? E1~mrnl.sof Croup I nnd Their compound,^ 9 ) Saturate 150 ml d n m e e n t r a t e d ammonium hydnxidesoluticm wilh wdium chloride. I h p small pieces of Dry Ice into the mixture. W h v d i d a ureriuitate fiwm?
Crrrup F-Oxidnlion-Rup /r I1 ond Thcir C < m p o u , d s 12) 1'0 I 0 ml 01 1 M Hp (NO.,).?solution add, drnp by drop, with stirring, several milliliters of I M 1
