The Cover

This month's cover is derived from an in situ high-pressure scanning tunneling microscope image of a platinum (110) surface under approximately atmospheric pressure of carbon monoxide after heating to 425 K for 4 hours. The difference in elevation between peaks and valleys is 420 pm. In this month's Viewpoints paper, which begins on page 161 *, Somorjai and Rupprechter describe how the surface changes structure when exposed successively to hydrogen, oxygen, and carbon monoxide. Modern analytical techniques are revealing that the positions of atoms in surfaces of metals and other solids change when adsorbed molecules bond to the surfaces. Such studies of surfaces are making possible improved heterogeneous catalysts and better understanding of friction, lubrication, and wear.

Related to the Viewpoints paper are this month's JCE Classroom Activity (page 176A *), which deals with liquid-vapor surfaces, and "Flying over Atoms", a CD-ROM from JCE Software (page 247 *) that includes animated sequences of "flying" over solid surfaces whose structures have been determined by scanning tunneling microscopy.

Chemistry with Household Products

Two articles deal with generating electricity from metals and fruit. Beginning on page 178 *, in the Chemistry for Kids column edited by John T. Moore and David Tolar, Stroebel and Myers describe inexpensive, portable, simple activities that invite children to discover links between electricity and chemistry. Swartling and Morgan (page 181 *) use everyday items like lemons to teach electrochemistry to freshmen and to children. Among other things, they power a calculator with three lemon cells. A more involved laboratory project for freshmen is described by Bosma (page 214), who uses a UV-Vis spectrophotometer to identify food colorings and measure pH. Those who want more information about the chemistry of food may want to consult "Food: The Chemistry of Its Components", the third edition of which is reviewed in our book review section on page 152 by Carandang and Ziegler. Speaking of books, Russo presents her opinion regarding the perfect text for a nonmajors course beginning on page 141 *. A simple but elegant approach to the big ideas of chemistry is her preference.

Curriculum and Teaching

The NSF is sponsoring five systemic curriculum initiatives in chemistry, in the hope of significantly changing the way our subject is taught. On page 185, Gosser and Roth report on progress to date in the Workshop Chemistry project, headquartered at City College of the City University of New York. Improving the Teaching/Learning Process in General Chemistry was the subject of a workshop for teachers held at SUNY Stony Brook last July. Hanson and Wolfskill report on this conference beginning on page 143 *. That there is considerable interest in curriculum and the learning process is also evident in the letters to the editor reacting to the June editorial that questioned whether chemical education had reached equilibrium. On page 138 *, Ramette suggests that we develop ideas for increasing the value of K_eq, and Schultz carries the analogy further, suggesting that there are forces pushing and pulling our discipline toward a broader definition of its purview.

Thermodynamics

For those who find chemical thermodynamics abstract and difficult, Glass and DeKock (page 190) have a suggestion: draw an analogy between mechanics and chemical potential, extent of reaction, and Gibbs energy. Jullien, Proust, and Le Menn discuss the evolution of Gibbs energy in a system where coupled, competitive reactions are occurring. Issues of kinetic and thermodynamic control of reactions are addressed beginning on page 194.