I.
Title: Mid-Evil Magic 
Recommended Grade Level: 5-12
Subjects: Physical Science/Intro to Chemistry
Author(s): Rhonda Schultz
School: Birchwood

II.
Objective: To distinguish that seeing is not always believing. This activity will use distinctions between Cu and Au to discredit a midevil magic.

Related State or National Science Education Standards
A12.4, C12.2, C12.4, H12.6, H12.7

III. 
Equipment and Materials
Zn dust, 6M NaOH, nitric acid, pre 1982 penny, evaporating dish, bunsen burner

IV. 
INTRODUCTION: Alchemy has its roots in the history of chemistry. Alchemy was a mixture of science, medicine, magic and religion. One of the main goals of the alchemy was to change lesser metals into gold. Producing gold was thought by the alchemists to be a major step toward everlasting life. Now let's take an imaginary trip back to the Middle Ages when knights were in fashion, fair ladies were to be saved, dragons were to be slain and alchemists were at work. The king has just called you for advice. The local alchemists has devised a way to make copper into silver and then gold. Your instructions are to perform the experiment, test the gold, and give the King your advice. Does he reward the alchemist or hang him as a cheat? Below are the alchemists symbols and their English translations.
? silver ? gold ç copper ? zinc µ heat or fire

The alchemists formulas for the conversions to gold are written below. Translate the formulas into English terms.
ç + ? = ?
? + µ = ?

PROCEDURE:
1. Clean 3 pre 1982 pennies with steel wool or a pencil eraser.
2. Place a small teaspoon full of Zn dust into an evaporating dish. Cover the Zn with 6M NaOH and heat until it begins to steam.
3. Immerse the clean copper pennies into the steaming solution. When bubbles of gas can be seen to escape, heating may be discontinued. The token will change to silver before your very eyes. Remove the tokens, rinse carefully with water and pat it dry.
4. Grasp the silver tokens, one at a time, with tomgs and heat in the outer cone of a Bunsen burner. The change from silver to gold will be quite sudden. Heat for 1-2 seconds after the change. Cool the hot tokens by immersing them in water.
5. We now have gold pennies. But, our work is not done. We need to prove if the tokens are real gold or not.

TEACHER DISCUSSION:
Discuss with students that all elements have their own unique set of properties. Have students research the properties of silver and gold. Guide them to three different properties that can easily be tested for in the lab. These particular elements should show very different properties if you test the densities, the hardness and the reaction with nitric acid. Run these tests on the gold tokens and on Cu pennies.

CONCLUSION:
Do you tell the King that the alchemist has succeeded or is he fooling the King. (Don't lose your head by a wrong decision!) Make sure you have valid proof.

V. Assessment: 
Have student's answer the conclusion question in their journal. Go around and discuss the results. Properties tested for in the lab should reveal very different results therefore, the alchemist has failed. What you have really created is the alloy brass which forms between Cu and Zn. Discuss with students that seeing is not always believing and the importance of running further tests to validate our answers. Also discuss with students how we might have gotten positive results for all of our tests. A gold coated coin could yield comparable results that would indicate the success of the alchemists. This activity is a wonderful discussion tool for scientific method and experimental procedure.