1. Check the date. The date is located at the bottom of the penny, just below the words "United States of America." If the date is 1941, then you have a copper penny.
2. Look at the color. Copper pennies are a reddish-brown color. If your penny is a different color, then it is not a copper penny.
3. Check the weight. Copper pennies weigh 3.11 grams. If your penny weighs less than 3.11 grams, then it is not a copper penny.
4. Use a magnet. Copper is not magnetic, so a magnet will not stick to a copper penny. If a magnet sticks to your penny, then it is not a copper penny.
If you have a penny that meets all of these criteria, then you can be sure that you have a 1941 copper penny.