Always wear eye protection during science experiments. Never handle sharp objects, open flames, chemicals, or other dangerous objects without adult permission and supervision.
Ask an adult to cut the orange into slices for you. This experiment works a little better with wedge-shaped slices (instead of circular slices).
Use the paper towel to dry as much juice as possible off one of the orange slices.
Dip one side of the dry orange slice into the baking soda so it forms a very thin layer.
Holding the baking soda side away from your tongue, take a bite of the orange. The juice from the orange contains citric acid, a weak acid that, when combined with the baking soda, will form bubbles of carbon dioxide, water, and a salt. (We recommend keeping a glass of water handy to rinse out your mouth!)