Magic Mixture - Apple Dunking

From National Geographic:

YOU WILL NEED

• An apple
• Half of a lemon
• Shallow bowl
• Water
• Knife (ask a parent for help)

HERE'S HOW
Peel and slice an apple. Cover one slice with water in a shallow bowl. Sprinkle a second slice with the juice of half a lemon. Leave another slice exposed to the air. Wait about an hour, then compare. The slice with nothing on it turns brown.

WHY?
When an apple is cut open, chemicals inside the apple combine with oxygen from the air to form a brown coating. The coating keeps oxygen from getting deeper into the apple. Water protects the first slice from oxygen in the air so it stays white. Vitamin C in the lemon juice binds with oxygen, keeping oxygen away from the second slice, so it stays white the longest.

Text by Julie Vosburgh Agnone
Illustration by David Bamundo