This is a great toddler activity to do. It involves lots of painting and listing to the sizzling the bicarb soda makes when you paint or drop vinegar onto the picture. It also makes a lovely swirly pattern with the paint.
What you need
2 tablespoons of bicarb soda for each colour
1/2 cup of vinegar
Mix 2 tablespoons of bicarb soda with a splash of water
Add a few drops of food colouring and mix it all together
Let your toddler paint on thick white card stock
Paint or slowly pour the vinegar onto the picture. It will start to sizzle and makes a great water colour picture.