Squeaks loves collecting shiny pennies, but sometimes he finds one that's sort of grimy and dull. Lucky for him, Jessi knows a really cool science trick to clean up those tarnished pennies! ---------- Love SciShow Kids and want to help support it? Become a patron on Patreon: https://www.patreon.com/scishowkids ---------- Looking for SciShow elsewhere on the internet? Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Tumblr: http://scishow.tumblr.com Instagram: http://instagram.com/thescishow SOURCES: http://buggyandbuddy.com/science-for-kids-make-a-penny-turn-green/ https://www.exploratorium.edu/science_explorer/copper_caper.html http://playfullearning.net/2012/06/six-ways-to-clean-a-penny-a-simple-science-experiment/ https://chemistry.stackexchange.com/questions/2765/why-is-salt-needed-when-using-vinegar-to-clean-pennies http://cleaning.lovetoknow.com/Penny_Cleaning_Science http://applenetwork.us/experiments/VinegarPennies.html https://water.usgs.gov/