This post is about a penny cleaning science experiment using kitchen staples. Did you know things like ketchup, salt, vinegar, and lemon juice will clean and brighten pennies? If you pennies are all bright and shiny, you can keep them in water overnight to allow them to darken for this experiment. Warning, children might like to do this over and over!

First, start with a dirty penny. These are highly available! If you have none, start a collection when you get change from shopping. We tried ketchup first.

Penny Cleaning Science Experiment Using Kitchen Staples

Then “wash” the penny with ketchup. This can be accomplished without touching the penny by putting it in a paper towel, folding the towel over, and then rubbing the two sides together over the penny. Using ketchup requires more elbow grease than some of the other options.


Then carefully observe with a magnifying lens. This can actually be done before and after cleaning the penny. clean-a-penny-with-ketchup

Penny Cleaning with Other Food Ingredients

Just be sure not to let the children mix the different cleaners together when penny cleaning. Things like salt might cause some pain to any tiny cuts they might have on their hands. This is a chance for them to wear gloves just like the doctors and nurses wear. At least have hand washing very accessible for them to rinse off salt or vinegar that may sting their skin. They should be supervised to prevent them from deciding to try household cleaners and other items that children should not use. The work page shows the ingredients that may safely be combined. Click on this link for an instant download of the science work along PDF here: shine-a-penny-experiment


We tried placing fruit slices on pennies for awhile and returning in about an hour. The lime slice worked the best with this method. We did not have to rub the lime juice. Actually, just leaving a penny in one of the proven methods to clean it will work if some time can be allowed.


You Might Also Like

You might also like our dancing dime experiment and video, as well as a penny observation page included in the Abe Lincoln’s Hat free printable. The penny page in the Abe Lincoln’s Hat free PDF explains how to use a magnifying lens. The 1-10 and 11-20 activities printables include easy coin graphing as well.


Thank you for reading! Carolyn


You might also like the science page for teachers and parents. science-free-page


This page has links to free science printable blog posts.  The printables and resources are available at the blog post links. There are more, so please use the search bar in the top right of each page to search for other resources.


The bubbling snowman is simply a version of using baking soda and vinegar which children never seem to become tired of doing. When the bubbling begins, it looked like it is snowing.  Please see the blog post here for more information and a short video.

The Bubbling Snowman and Science Fun

The bubbling snowman is simply a version of using baking soda and vinegar which children never seem to become tired of doing. When the bubbling begins, it looked like it is snowing.  Please see the blog post here for more information and a short video.


Information about a free magnets printable is at this blog post. The printable will be found in our free eMembers area.


Have you see the dancing dime experiment to demonstrate that warm air takes up more space than cold air? See the post at this link for more information as well as a very short video.


Free student interactive notebook printable for studying plants on the prairie at this blog post. What plants and animals live on the prairie? Find out in this printable.


free printable with matching cards for teaching about bogs is at this blog post. The suggested text is not required for using the cards in the PDF, but some source of information would be nice to have on hand.


The nocturnal animals printable in French and English is available with both realistic animal photos and with clipart. Teachers may select which option they prefer. The French cards are in a separate section in the printable, so if only one language is wanted, just print those pages.


Observe and journal about a tree for an outdoors science activity. Visit the same tree a each season of the year to notice what is happening. More information and a free PDF is available at the blog post.


Social distancing animal paws and hooves sit and stand spots freebie in two printing sizes.


Science experiments at home using test tubes, nature print paper activities, and breaking open geodes. See the information at this blog post.


STEM with recycled newspapers, old-fashioned fun


Build a solar oven and bake smores (free printable at the post)


Leaf-shaped 3-part cards printable — download at this blog post link.


Vertebrates/invertebrates sort, free PDF, instant download at the blog post.

Changing Seasons Graphing Activities

Northern and Southern Hemispheres Changing Seasons activities printable for the center or as a guided activity, free at this link.


62 page printable where children may sort singular and plural animals words, make an emergent reader by cutting and stapling pages, as well as use their Sudoku skills. Free download at the post.


Math and nature Fibonacci posters can be downloaded in the free eMember area. 


Solar Bead Necklaces are amazing for children but do not tell the secret while inside and working on the project. Let children discover for themselves how the sun causes these beads to reveal their colors.  They will be happy to share the information with you! For information please see the blog post at this link.


Watch Me Grow, Rabbit is a nonfiction book for children with facts, information, and photos that show how rabbits grow and live. The free printable at the blog post has a worksheet and answer key to accompany the text.


Cleaning pennies with kitchen staples such as ketchup.


Grow crystals over night using tissue paper instead of coal, and a few household ingredients.  See information and printable directions which open here.

Animal Group Names Coloring Pages Freebie

Another fun page is an animal groups coloring page freebie.


Here is another free lesson with an activity where the students act out the inner ear to help them understand how we hear.


Two freebies for Tracks in the Wild by Betsy Bowen — work page, answer key, and 3-part cards.

Glowing Ice Cubes Easy Home Science Experiment

Glowing ice cubes easy home science experiment might just be the thing for early dark evenings during winter!

plant growth observation journal

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