Final answer:
Plants use sunlight, air, and water to make food through photosynthesis. The tarnishing of a penny is caused by a chemical reaction between copper and substances in the air.
Step-by-step explanation:
All plants use sunlight, air (specifically carbon dioxide), and water to make their own food through a process called photosynthesis. Photosynthesis is how plants convert sunlight into energy by producing sugars. Just like plants use sunlight to make food, a penny tarnishing is a result of a chemical reaction between copper in the penny and substances in the air, such as oxygen and sulfur.