A chemical reaction!
We have been engaged in a scientific experiment over the last few days.
The children have been shining pennies by using lemon juice and salt.
The children start by choosing a dull penny. They put it on the plate and rub the mixture of lemon juice and salt on the penny with a cotton swab. Once shiny, they rinse it off in the water and pat dry. They then take it and put the penny in the shiny container.