In June and July, the Contra Costa County Libraries invited Cal ACS to participate in four Exploration Station events across the eastern part of the county, with the theme of sustainability:
- Brentwood Library – June 14 | 11:00am – 1:00pm
- Bay Point Library – June 15 | 2:30 – 4:30pm
- Pinole Library – June 29 | 11:00am – 1:00pm
- Danville Library – July 11 | 1:00 – 3:00pm
I took on the first two events myself (a couple of other volunteers had to drop out at the last minute) and I reprised our Earth Week 2023 activities, making alginate gels and making oxygen using solar-powered electrolysis. At each site, Contra Costa County library staff graciously helped out as we welcomed dozens of families who were eager to try some hands-on science:
Kids were eager to collect their colorful alginate gels, which they created as worms, salamanders, and beads by adding 2% sodium alginate solution to a 10% solution of calcium lactate. Since the materials are food grade products, there was no need for protective equipment. Older friends and parents were ready to accepts copies of Celebrating Chemistry, Periodic Table wallet cards, and other souvenirs.
Michael Cheng led the team at the Pinole Public library, assisted by Vanessa Marx and Elaine Yamaguchi. As he reported, several other community organizations were present, and about 75 visitors stopped at the Cal ACS booth to make slime (with polyvinyl alcohol and borax) and create UV-detecting bracelets with color-changing beads.
Greti Séquin joined me at the Danville Public Library, and she prepared this report:
On a hot, sunny afternoon, children of all ages, together with their adult companions, visited the Cal ACS booth on the lawn in front of the Danville Library. They were invited to shake vials with small samples of plant materials in water and had fun observing the formation of bubbles in the samples containing soapy saponins. A model of a soap molecule and a complete, four foot long California soap root plant (Chlorogalum pomeridianum) decorated the exhibit.
Our guest then compared fragrant plant leaves with small samples of plant extracts in vials, trying to guess the identity of the extracts. They could then build molecules of some fragrance compounds, such as geraniol or vanillin, using our molecular model kits. While older children patiently built the models according to the illustrated structures, most younger children had fun building their own “fantasy” molecules.
UV-detecting beads were popular with children (and adults), who craft their own bracelets and observe the changes of the beads (colorless in the dark and but brilliantly colored in sunlight). They could also observe the power of sunlight, as electricity from two small solar panels split water into its chemical elements. See below for the Danville event photo gallery.