Splash goggles, lab coat or chemical apron with long sleeve shirt, covered legs, closed toed shoes, long hair tied back, and something to write with. Competitors should also bring the optional materials listed below, or they will be at an extreme disadvantage.
NC Only: 3. NC will only be focusing on parts 3.a.(powders, and liquids), 3.biii. (hair & fibers), 3.c (chromatography) and 3.d.i. (fingerprints). Other topics listed in the rules will not be addressed at regionals, but MAY be covered for the state tournament test. Additional questions may be asked on general lab safety and procedure. (9/9/16)
Description: This is a Lab based event. Teams will be given a crime scenario which they will be asked to solve based on evidence they gather and test. The evidence topic for 2017 in NC is powders, liquids, hair, fiber, chromatography & fingerprints. Teams will then be asked to analyze the information they have gathered to identify a suspect and solve the crime.
Teams MUST bring chemical splash goggles, safety gear, and a writing instrument. Teams may also bring spot plates, test tubes and test tube holders or any containers in which they can perform the tests, popsicle sticks, spatulas, plastic spoons, etc. for handling materials, pH paper, a ruler, hand lenses or loupes, paper towels, a disposable cup for solid waste, writing instruments, and 5 sheets of paper with information in any form from any source. Sheet protectors are encouraged.
***SAFETY ISSUE*** In addition to OSHA approved chemical splash goggles with indirect vents, teams also MUST wear closed toed shoes,pants/skirts that cover legs to the ankle, AND a lab coat/apron that reaches below the knee or they will not be allowed to participate. Long hair must be tied back. In addition, any teams seen handling materials in an unsafe manner will be disqualified from the event. ***SAFETY ISSUE***
Event Leaders will provide a proper lab environment, all evidence to be tested, additional equipment necessary to perform tests on the evidence, the official test and answer sheet.
High score wins. Points are earned for proper identification of evidence as well as analysis of the crime. Ties will be broken by the best Qualitative Analysis (3.a.) score.
- Be sure to follow all safety requirements! Safety issues will NOT be arbitrated.
- Event leaders will not answer questions on testing procedures (for example- how to perform a burn test on fibers) nor will they provide a copy of the rules or a list of the possible unknowns. Teams should already know procedure, and should include a list of the possible unknowns in their allowed notes if they cannot remember. Event leaders WILL answer safety questions, and stop students from performing a test in an unsafe manner.
How to identify unknown fibers based on their flame test characteristics. Start with fibers you know and test them all, being careful to observe and record all characteristics of the test. It is much easier to make your own chart to follow than to download one, since you will recognize the same characteristic in a fiber more easily if you described it in your own words rather than trying to match it to someone else's description.
How to do a polymer density test. Follow the flow chart and see if each polymer sinks or floats in the liquid it's placed in to determine its relative density and come to an identification. If a polymer is floating, make sure it is actually floating and not sticking to the surface via surface tension. Do this by forcing the pellet to submerge, then see if it floats back up.
Performing powder tests in the Forensics event. The process here is the same as in the Crime Busters event.
More powder tests. Always write down everything!
Performing chromatography tests. Ideally you would not want the filter paper to touch the side of the cup, you would suspend it from a straw or rod of some sort.
The divide and conquer approach. One teammate works on powder identification (note the proper use of wafting to identify smells) while the other teammate works on the fingerprint IDs.