Evidence Evaluationfrom the Crime Scene

CSI Agents: Salil K. Julianna I.Leah H. Kristin H.

Physical Properties

A physical property is a characteristic of matter, and does not change the chemical makeup of a substance.

Example of Physical Properties

Color Odor Density Viscosity Mass Transition points Ductility Malleability Texture Conductivity, etc.

Chemical Properties

A chemical property is a characteristic of matter. It’s a property that describes a substance or substances

chemical makeup. It cannot be determined by your senses, but must be

changed in some sort of chemical way. It is an ability to react with other substances.

Examples of Chemical Properties

Flammability Combustion Oxidation Heat of Combustion Electromotive Reactivity with water reactivity with vinegar Reactivity with iodine Etc.

Magnetic

Metal Evidence Evaluation

SteelAluminum

Metal Evidence Evaluation

Identity of Sample 1 is : AluminumSupporting evidence:Non-magneticDensity – 2.5 g per mLSilver coloredMass = 3.8 gramsLength = 4.7 cmVolume = 1.5 mL

Metal Evidence Evaluation

Identity of Sample 2 is : SteelSupporting evidence:MagneticColor is brownDensity – 7.85 grams per mLMass – 2.3 grams Volume – 1 mLLength – 4 cm

Liquid Evidence Evaluation

Evidence X- Water, Alcohol, or Vinegar Based on the evidence and our observations, we have

concluded the liquid is alcohol due to the fact that all of the test results match up exactly for the mystery liquid and the alcohol

Physical Properties Chemical Properties

Mystery Liquid Properties

Clear Mass: 17 g Volume: 20 mL Density: 0.85 g per mL Odor is alcoholic

Flammable

Mystery Liquid Evidence

Mystery Liquid Video

http://www.youtube.com/watch?v=a3x0UDU5zQc

Burning Alcohol Video

http://www.youtube.com/watch?v=_dG3OX0FFkI

“Burning” Water Video

http://www.youtube.com/watch?v=1oeEumV7yx8

“Burning” Vinegar Video

http://www.youtube.com/watch?v=6MJXOtFMTDI

Powder Evidence Evaluation

Water Vinegar IodineBaking powder Rises

Bubbles BubblesFizzes

Turns black

Baking soda No reaction Bubbles Fizzes

No reaction

Corn starch No reaction No reaction Turns black

Baby powder Bubble of waterhydrophobic

Bubble of vinegar

No reaction

Mystery powder Rises bubbles

BubblesFizzes

Turns black

Summary of Findings

We conclude that the materials found at the A West crime scene were: The mystery metals was:The mystery liquid was: mmmmm The mystery powder was: hjdhdh

Mystery Samples

SteelAluminum

Metals Identity

Results