We used milk, a plate, food colouring and washing up liquid. The washing up liquid pushed the fat molecules in the milk away from it (this is how it washes your dishes) and made a lovely marble like pattern in the milk! It was very cool to watch!
UPDATE!!! Volcano made and erupted!!! We used baking powder, clay, food colouring and vinegar to create mini eruptions.
First we made the volcano, then we stuffed it with paper and added the baking powder and food colouring. next we added the vinegar and made it erupt. The reaction between the vinegar and baking powder even added the bubbles and sound effects you see in real volcanos.