Script: Welcome to the Ingenia Forensic Chemistry Lab! Today you will be forensic chemist apprentices. We have a mystery to solve. The chef at the Ingenia Master Kitchen found a bunch of unlabelled bags with mystery white powders inside. The chef can’t use these mystery powders to cook with until they are identified. How could we find out what they are? (Give students an opportunity to give some ideas) One thing we could do would be to taste them but that could be very dangerous. These powders could be something that shouldn’t be eaten like a medicine, a drug or a poison. (pause for effect). As you learned yesterday in the chemistry lab, it is not safe to taste or smell unknown substances. Forensic chemists solve mysteries and sometimes help the police to solve crimes. They investigate different substances found at crime scenes in order to identify them. Today, your job is to find out what these mystery powders are. Each team will get one bag of mystery powder you need to identify.
Distribute the ziplock bags with mystery powders, one for each team. The mystery powders will be salt, sugar, baking powder, baking soda, washing soda, cream of tartar and cornstarch.
Chemists study the physical and chemical properties of matter. Matter is everything around us that has a mass and takes up space. Let’s watch a video to learn more about physical and chemical properties: Matter: Physical and Chemical Properties (https://study.com/)
Note to teacher: Watch this video to understand the process of this investigation before the lesson: Forensic Science| Mystery Powders (Chemistry) (www.youtube.com/@MichelleGayScienceTeacher)
Script: You are now going to study the physical and chemical properties of several samples of known white powders. Then you will test your mystery powder and compare it to the samples to determine what it is. The known white powders you will test are: salt, sugar, baking powder, baking soda, washing soda, cream of tartar and cornstarch. As you investigate and test these powders, record your observations on this chart:
Mystery Powder Observation Chart
Each team will report to the group the results of their experiment and will share what their mystery powder is. The mystery powder is cornstarch.
**This can be added to the HW activity if you run out of time.
Script: Sometimes forensic scientists go to a crime scene and collect fingerprints in order to find out who was present at the scene. Your next assignment is to collect and observe fingerprints.
*Note: Activity adapted and inspired by: Be a Fingerprint Detective (https://www.scholastic.com/)
Watch the following video:
What is forensic science? Meet Forensic Scientist Gina Presley (www.youtube.com/@MichelleGayScienceTeacher)
Script:
Review the vocabulary with students, then play a game where you give each student a card with an example of a property and they have to sort themselves as either physical properties or chemical properties on opposite sides of the room.
Physical Properties: it is a characteristic that can be observed using the five senses, it can be measured and it doesn’t change the matter. Examples: color, texture, size, taste, smell, solubility, density
Chemical Properties: it is a characteristic that can be observed during a chemical reaction when a substance changes into a different substance. Examples: flammability, toxicity, acidity, oxidation, reactivity
Matter: everything around us that has mass and takes up space.
Create a fingertip profile of a member of your family at home. You will need paper, a pencil and some tape.
