PBL 1 Unknown Crime Scene Evidence Identification S

PBL #1 Unknown Crime Scene Evidence Identification

S 8 P 1 d. Distinguish between physical and chemical properties of matter as physical (density, melting/boiling point) or chemical (reactivity, combustibility).

CSI agents frequently find substances and items at crime scenes and must identify them. The agents use the properties of the substances to guide them to an identity of this matter.

Problem Your team is being called as CSI expert witnesses at a trial. You need to prepare a presentation to prove to a jury the identity of the evidence (matter) found at a crime scene. Use your expertise of physical & chemical properties in your presentation.

The evidence found at the crime scene that you must identify: �A white powder �A clear liquid �A metal

Since you are CSIs in training, your CSI trainer has provided you with some preliminary findings. The white powder is one of the following: 1. Baking soda 2. Baking powder 3. Baby powder 4. Cornstarch The clear liquid is one of the following: 1. Water 2. Isopropyl alcohol 3. Hand sanitizer The metal is one of the following: 1. Copper 2. Aluminum 3. steel

Your presentation must include: v The identity of each substance based on the data collected from your observations and experiments �The physical properties used to identify each �How you used the physical properties to differentiate between the possible substances �The chemical properties used to identify each �How you used the chemical properties to differentiate between the possible substances �Pictures that support your findings

You will be cross-examined, so be……… PREPARED!!