Celebrating 75 Years!

The Cover

This month's cover shows flame tests from the Chemistry Comes Alive! CD Volume 2. Solutions containing different elements were sprayed into a flame and the colors recorded on videotape. Most are spectacular when seen close up. An abstract describing the digitized video on this CD-ROM appears on page 927 *. You can play it back on any computer manufactured within the past few years, and the chemical reactions and other content have been organized to correlate with typical introductory textbooks.

NEACT 100th Anniversary

This year marks the 100th anniversary of the New England Associationof Chemistry Teachers (NEACT). Madeline Goodstein provides a brief history of NEACT (page 815 *), and the second of three invited keynote lectures by William Jensen at NEACT's 57th summer conference begins on page 817 *. Reports from NEACT began to appear in this Journal's first year of publication and it is the oldest of many similar organizations for chemistry teachers. These organizations make important contributions as a result of their members' efforts on behalf of our discipline. For example, DivCHED programs at recent ACS meetings in San Francisco and Dallas were greatly enhanced by the work of the California Association of Chemistry Teachers and the Association of Chemistry Teachers of Texas. And the very first issue of this Journal reported the initiation of the Maryland Association of Chemistry Teachers, which is the same age as the Journal.

Conceptual Understanding

In addition to Jensen's NEACT lecture, a number of papers in this issue deal with the concepts of chemistry and how to help students understand them better. Pushkin (page 809 *) argues that it is important to develop both conceptual (qualitative) and algorithmic (quantitative) skills in introductory students. The late George Atkinson (page 849) provides an in-depth view of a thermometer as a scientific instrument, using this simple device that students are familiar with to develop principles of design that apply to all instruments and chemical measurements. Duchovic (page 856) describes a number of techniques that can be used to communicate a conceptual framework for introductory chemistry. Deckert, Nestor, and DiLullo(page 860) describe a guided-inquiry approach to physical chemistry laboratory that extends the similar approach already in use at Holy Cross and other colleges. Gilbert (page 851 *) develops a simple, logical connection between the calculation of percentage composition and determination of empirical formula.

Chemical Structure and Physical Properties

This month we have a number of papers that deal with the relationships between atomic-scale chemical structure and properties of bulk matter. Baker, George, and Harding (page 853) describe a workshop approach in which students get hands-on experience with structures of stereoisomers. Mosher and Ojha (page 888) report on a physical organic chemistry experiment in which the degree of mixing of s and p orbitals to form hybrid orbitals is related to structure. Hunter et al. (page 891) have developed a series of related synthetic experiments in which each student can make a slightly different product and explore its properties. Kim and Musfeldt (page 893) show how molecular modeling and thermal analysis can be used to help students understand structure-property relationships for polymers. Conventional ideas about properties of ionic and covalent compounds are found wanting by Gillespie (page 923) who argues that bonding in BF₃ and SiF₄ is mainly ionic and these compounds are gases because the radii of the central ions do not allow a crystal lattice to form with appropriate coordination numbers of fluoride ions around them.

Summer Reading

Be sure to check our book review editors' suggestions for summer reading. Ed Walsh, Michael McCallum, Jeff Kovac, and Hal Harris all have recommendations beginning on page 806 * that sound enticing and should make a lazy summer afternoon both interesting and enlightening. The same can be said of Lambert's book on applications of chemistry to archaeology, which is reviewed on page 808 *. There are certainly lots of great books about chemistry, and our book reviewers provide you with excellent reports on them.

* designates articles of special interest to high school teachers.