If they're old enough, yes. Solid copper pennies -- those minted prior to some time around 1983 -- are worth more than 1¢ per as raw copper. I believe it's technically illegal to melt down US coins, but once they're melted and cast as ingots, who's to know?
That's why the Mint started making pennies out of copper-plated zinc in the early '80s. That led to my favorite high school chemistry class trick. Nitric acid dissolves copper but not zinc, and hydrochloric acid dissolves zinc but not copper (I think -- I might have it backward. It's been a long time).
Trick part 1: burn off the copper, and you have a silver-colored penny that is pretty much indistinguishable from an intact penny other than by color. You might be able to pass those off as rare WWII steel pennies, but I wasn't conspiring to commit fraud. I just thought it was neat.
Trick part 2: with a handy pocket knife, nail file, X-Acto, or the edge of a desk, make a notch in the edge of the penny so you can see the zinc. Dissolve the zinc, and you have a hollow copper shell barely thicker than crepe paper. Then you can hold it between your thumb and forefinger, showing your audience what appears to be a solid penny, and then crush it with nothing but finger pressure.
Took me a while to get tired of that one. Even though it only worked on freshmen and sophomores who hadn't taken chemistry yet.
I had a lot of fun in the chem lab. My lab partner (and best friend) and I usually finished our projects early, so in our spare time we each lined up eight test tubes in a rack and filled them with varying levels of water so, eventually, after a lot of tweaking and tuning, they formed a C Major scale when lightly tapped with a glass stirring rod. When we finished the project, we held a little recital for our classmates.
If Mrs. Strong, my chem teacher, didn't have a sense of humor, I probably wouldn't have graduated high school.
But I digress.
The copper-clad zinc pennies burn with a charming blue and green light wehn tossed onto the fireplace embers.
The copper-clad zinc pennies burn with a charming blue and green light wehn tossed onto the fireplace embers.
The Lincoln tophats floating across the bubbling surface might tip off the feds. :-)