– Place different solids (iron, sand, wax, ice) near a heat source. Record which melts first. Connect to real-world melting points.

Over hundreds of reactions are possible, such as mixing water with sodium for an explosive reaction or creating iron oxide (rust) by adding oxygen to iron.

Create a chemical reaction that produces a gas (bubbles or smoke), then trap that gas so it pushes something. Hint: Try vinegar + baking soda inside a closed space with lightweight pixels like “dust” or “seed”.