This document outlines how the activity might be linked to the NGSS as part of a classroom lesson.
This activity involves the use of chemicals. We strongly discourage this activity from being performed by anyone other than a trained chemist. Science Discipline(s) Chemistry This activity is best conducted at the middle school or high school level. Topics Reduction, oxidation, metal alloys Activity Title Gold and Silver Pennies Materials Bunsen burner
- 20 mL of 3M NaOH
- 0.1 g zinc dust
- Evaporating dish
- Hot plate
- 200 mL beaker of water
- Steel wool
- Put zinc dust in the evaporating dish.
- Add 20 ml of NaOH solution to the dish on top of the zinc
- Set hot plate to medium heat and place evaporating dish on top.
- Use steel wool two polish two or more pennies.
- After five minutes of heating on the hot plate. Place the clean penny in the solution until it has been fully coated with zinc and turns silver.
- Remove the penny from the dish with tongs and place it in water. When penny has cooled down, clean it with a cloth to remove excess zinc.
- To turn it gold, place penny in the flame of the Bunsen burner until it turns gold. It is possible to also use a hot plate to heat the pennies to avoid an open flame. (Do not over heat)
- Place penny somewhere safe to cool.