I provided a dish, a jug (to be the ‘volcano’), vinegar, bicarb soda, and food dye… the kids did the rest.
They had a *wonderful* time. Afterwards, their father took them through the chemical makeup of the compounds, ions, molecules, reactions, bases, acids, all those things that aren’t my speciality. Later, we discovered that the mixture had eaten through the finish on the table! Good thing it was a cheap eBay table that is too small for our family now. All future science experiments will be conducted outside, and I am now sold on the cleaning power of vinegar and bi-carb soda.