Tri-Valley Innovation Fair 2025

After missing this festival a couple times due to schedule conflicts, Cal ACS returned to the Alameda County Fairgrounds in Pleasanton on Saturday, April 12th for a fun-filled day of hands-on science. Charlie Gluchowski and I arrived early for setup, assisted by Angi, one of his students at Las Positas College. We were soon joined by Dan Calef, another outreach veteran. By the time the crowds started to arrive at 10 AM, we were ready with several activities related to this year’s Chemists Celebrate Earth Week theme, “Glaciers: Hot Topic, Cool Chemistry.”

Kids had fun exploring the aquarium tanks with model glaciers and ice bergs; as the glacier melted, sea-level rise was unmistakable. By placing blue-dyed ice cubes in either fresh water (dyed yellow) or salt water (3.5% salt by weight, dyed red) they could observe what happens when ice bergs melt — the cold, fresh water floats on the denser seawater, but sinks in the less dense fresh water.

Meanwhile, Charlie and Angi were introducing visitors to the ever-popular UV-detecting beads. These beads are white when stored in the dark, but turn vivid colors when exposed to UV light. Every young scientist was eager to make a necklace or bracelet with these beads (combined with other colorful pony beads):

Using a digital thermometer, we could also demonstrate freezing point depression when we added salt to ice:

I had to leave at lunch time, but Charlie and Dan stuck it out until closing time at 5 PM, giving away our entire stock of CCEW 2025 edition of Celebrating Chemistry in the process, along with hundreds of Periodic Table wallets cards and other CCEW souvenirs. Another great day for science outreach!

Alex Madonik