aqljo asn a4ueqs spapnls aql jo suo!wuasqo amos palaaf -ralu! pue qods a!4aleqs maj e le Bu!moqs aql paddols I

.uog -3qord ar(a 30 %u!na~ aql 'asrnoa jo pue 'raurnq aql Bu!sn 'sapem p!maqa jo pods!p 'sluaqos a!ue810 jo asn 'saseq pue spy roj sanb!uqaaq Bu!$nl!p 'saseq pue sp!w Bu!~pueq 'sIea!uraqa jo a2erols pue Bn!lpueq 'sraddoqs qu! Bu!qnl SSBTB Burirasur 'sprnbq TO Burrnod aTes 'slarnq Butsn 'samnlon

2rnisar;nur ue auramoa oi Kiruiiroddo ue sr arau ,sanbrwaa?

... ...... . . . . jo lnd fguassa ue s! &lap Kroleroqel leql aar4e sn jo I[V .raqaeal Wop!q aql qqm aseqarnd aql areqs uea noK

A sdeqrad .sapas aqlp ved s!q? puamwoaar h@!q I we12ord u hroieroae~ r(11srmaq3 a43 ror sanbruqaal Klaps koleroqel " ....... . . 1 a!seqjo ma!nar ro Ma!nard pons bran e aq ol suiaas pus ~roiei

s -0qeI Kqs!maqo aql oq alqeqdde Kraa s! auo %red 'ranamoH

we13 hBo~o!q aql roj pau%!sap s! sa!ras apgs $red-oM? S~J,

.8u!uu!Baq aql mog sBu!yaeard hm jo amos paaroju!ar sa!ras s!q& .sanb!ixqaq pue luamdyba kqer -oqel aldm!s aql jo amos ql!~ paqu!enbae 'Pqmamos amoaaq ...... ~eu sinamis aul ralm ~aiaar,e se sarras srql pasn I .laqrem

.... ... . . &u!rd prapuels aql uodb puadap 01 peq aneq I sraaK aql ran0 .Kroleaoqe1 aql u! Klajes lnoqe p~s aq louuea q4nou3

20901 AN 'sU!nld *!qM ooz X08

qmd suo!lsqunmmoD 3UI 'pu!qUE&AJ PUB 83Ua!3S:?J3I?ddnS

0Y6F1$ 233IIId

?vuo3 i'du!m!l

pw 'uo!y!p 'a~has 'I(l!pnb aa!on poo'd anq IWEJ~U aql saoa . ~LJO?JBJS!~E~ Bu!l!pa aql SI . ia1qqdaaaE punos aql SI ipasn hlan!lJajja pue

pampo~dar [[am sqdw0~oqd aq ueql mqlo spnstn aql aiv . ian!leu!aam! pw aq2ajja hqdm8oloqd aql SI . sa!~l~nb lo>?uyJaj

?quipment. Some of these observations were quite comical, md the students added their own tales of "wrongdoings." In general, they felt that they understood some of the reasons ~eh ind my constant recriminations. I received very positive reedhack and the "proof of the pudding" was the improvement ,f their laboratory techniques, a decrease in glass breakage, md an increase in their awareness of safety in general.

A teaching guide is included which contains the entire script, notes to supplement some of the frames, and six sug- tested activities that the teacher can use to demonstrate some 3f the techniques.

Energy and Entropy in Chemical Reactions

TIME: 11 to 12 min for each filmstrip FORMAT: 2 color filmstrips with 2 cassettes (manual and

audible signals) Teacher's guide induded

CAT. NO.: SCC82l (cassettes) SCR821 (records)

PRICE: $53 SUPPL1ER:Prentice Hall Media

ServCode SC 4 150 White Plains Road Tarrytown, NY 10591

This series consists of twoparts: "Energy and Enthalpy in Chemical Change" and "Entropy and Free Energy: Why Chemical Reactions Occur." These filmstrips use physical examples to illustrate the forms of energy. Graphs are used to explain endothermic and exothermic reactions. Many basic chemical principles are illustrated in both these filmstrips. In the 11 min it takes to show the filmstrio, too many princi- ples are developed, which ruts down on i& &efulness>or the entire class. I found it more useful as a review lesson and for individual students who needed to catch up. Our library has a Dukane unit which 1 am able to lend to my st~alents to use on their own time.

A teacher's guide is provided and the entire filmstrip with both visuals and narration are reproduced. Each booklet contains three worksheets that may be copied by the teacher for use with the class,

Chemistry: The Forces in Solids, Liquids, and Gases

TIME: 15 to 16 min FORMAT: 5 filmstrips with 5 cassettes (automatic and

. , CAT. NO.: 109 PRICE: $120 SUPPL1ER:Berwall Productions, Inc

839~tewart Ave. Garden City, NY 11530

One of the more difficult t o ~ i c s for chemistrv students to comprehend fully is the chemical bond. Perhaps one reason to he offered for this difficulty is the lark of visual means to demnnstrate intermolecular and interionic attractive forces. This fi lmstri~ consists of 5 parts which fairly clearly demon- strate numerous phenomena.

Each of the filmstrips highlights one phase of the topic. The fust one, "What Holds Solids, Liquids and Gases Together," demonstrates the differences between covalent and ionic compounds using sodium chloride models and ammonia models. Electronegativity is explained along with Van der Waals forces. The second one. "The Hvdroeen Bond." com- ~~ ~ ~ ~~~ ~ ~~ . .. pares tne hniling points of the hydrides and the nature of the hvdrwen bond in water. The third one. "The Hvdrocen Hond . who cares?" is the one you can ~eavd out if you are pressed for time. I t discusses the hydrogen bond by comparing the

densities of ice and liquid water. The fourth one, "Network: the Endless Bond" was an interesting one for my students since they grew tired of my endless blackboard scrihhlings, which I thought clearly demonstrated the bonding in dia- mond. In fact, this filmstrip was a lifesaver. I t discusses the pruperties of diamond, graphite, quartz, using electron dot diagrams, structural dingrams, and molecular models. The fifth one in the spriei, 'The Honding in Metals," discusses metallic properties using electron dotdiagrams and electron confiaurations. Comoarisons are made between metals and non-metals so that astudent will see the difference between the properties of theso iut~stances.

A study guide is offered with the set, and additional ones are three dollarseach. 1 did not find them particularly useful, since I used the set in class as one unit. But if vou are more inclined to have your students do independent study, these euides mav he iust rinht for vou. There is no teacher a i d e . " iffered so you will ha; to preview theentire series befo; you present any part to your class.

Introducing Chemistry: How Atoms Combine

TIME: 11min FORMAT: Color Film CAT. NO.: 1666 PRICE: $160 SUPPL1ER:Coronet Films

65 East South Water Street Chicago, IL 60601

I do not usually use films with my chemistry classes, because if they are too long and too boring, the students fall asleep. Sometimes I do. too. But if they are short, to the point, and right on target, I use them.

-

The oarticular film is only 11 min long and with an intro- duction on my part, I use this a t the heginning of my unit on bonding. It shows diagrammatic views of the atoms with their valence electrons. An explanation is given of polar covalent, nonoolar covalent, and ionic bonding. I t presents an especially useful animated view of electron motion.

+ Question Section

J. M. from Texas writes to ask if anyone out there knows where to purchase films for the CHEMS courses? Are there any other good visual aides that could supplement this pro- gram? I am also looking into this for you, J. M.

Your Turn

Now it is your turn. Do you have a favorite film, filmstrip, slide-set that you find helpful in your chem- istry class? Would you share this with us? Please put information in the form shown below and send it to me. We will print your comment in future issues. Please indicate if you wish your name to appear on the re- view.

Format for Reviews TITLE: ...-.... 111wm:

FORMAT: CATALOG NO.:

SUPPLIER:.

COMMENTS

448 1 Journal of Chemical Education