Chancellor and UCSD Chemistry
Prof Use Glowing Pickle to Pitch Thrill of Science to Kids

By Kim McDonald I October 3, 2005

How do you make a pickle glow? Chancellor Marye Anne Fox and Chemistry Professor Jim Whitesell unveiled the secrets to this and other mysteries of basic chemistry during the summer in a special guest appearance at the Elementary Institute of Science.

The institute, located at 608 51st St. in San Diego, operates hands-on science enrichment programs during the summer, after school and Saturday for students ages 7 to 13. Shrinking school budgets and the growing sizes of classes have restricted the ability of local teachers to demonstrate real-world applications of science. So the non-profit institute fills that gap by connecting students to science they can touch, feel, smell, taste and see when their natural curiosity is at its peak—during their elementary school years.

The institute has long had a relationship with UCSD, since many of its instructors, such as Mike Saxton, a senior in biology, are UCSD students. Saxton gave a laboratory demonstration to his own group of students as Chancellor Fox and a group of senior UCSD officials watched during their tour of the institute before the Chancellor’s chemistry demonstration to a gathering of more than 100 students and teachers.

With many students at the institute from ethnically diverse and low income families, the Chancellor took advantage of her visit to encourage a group that might not have previously considered becoming scientists to not only think seriously about it, but to consider accomplishing that goal at UCSD. So in addition to Professor Whitesell, the Chancellor brought Nicole Jackson from UCSD’s admissions office and Jorge Huerta, a theatre professor and the campus’ chief diversity officer, to help her convey to the students how they can best prepare themselves for admission to UCSD and a career as a scientist or engineer.

While the students listened intently and asked questions about their future prospects, it was clear the highlight of their day was much more immediate: trying to figure out what would happen after Professor Whitesell connected electrodes from a variable transformer to a pickle he had just plucked from a briny jar. With lights dimmed low, he slowly turned the voltage higher and higher until the pickle began to snap, sizzle and then—to the “oohs” and “aahs” of the students—began emitting a yellow glow.

Why did it glow? And why yellow, the UCSD chemists asked their audience. The effect, explained Professor Whitesell and Chancellor Fox, also a professor of chemistry at UCSD, is due to the pickle’s salty nature. Sodium glows yellow when exposed to an electrical current (or a flame). And the reason it emits light is that this energy transfer boosts the energy of the electrons within sodium atoms. When these sodium electrons drop back to lower energy states they emit energy as light, or glow. It’s the same process that makes neon or argon gases glow in a neon sign, Professor Whitesell explained. The energy emitted is different for each element. Thus, neon glows orange, sodium yellow, and lithium pink.

The UCSD chemists’ demonstration is an example of the way the Elementary Institute of Science engages its students in the discovery of basic science principles. For more information on the institute and its programs see www.eisca.org or call 619-263-2302.