1. Science Olympiad Crime Busters (B)
Hints, Tips, Things to Prep

2. Overview Story arc presents Table of Results suspects
types of evidence
which exhibit goes w/ which suspect
Table of Results
Evidence
Powder
Metal
Liquid
Hair
Chro
Crime Scene P1 P2 P3 P4 M1 M3 M4 M2
Suspect 1
Suspects
Suspect 2
Suspect 3

3. Prep Pack the Student Kit see list in Rules ex: hand lens(es)
ex: small containers (spot plates / well plates?)
plural
have enough to run all tests w/o washing
waterproof box for dirty
ex: paper towels
does not specify all the same type
pack plenty (include enough for cleanup)
Read the rules…
build the kit while practicing the tests

4. Categories of Exemplars
Powders
Metals
Liquids
Hair
Fibers
Chromatography
DNA (results)
Fingerprints
Recyclable Plastics
Shoe Prints / Tire Tracks
Required Groups - 55%
Optional Groups – 15%
Analysis – 30%

5. Prep: Powders, Metals, Liquids
Develop a Flowchart
Practice the tests
chart of results in binder
count equipment needed for student kit

6. Prep - Powders Add Water Swells  Gelatin Bubbles  Alka-Seltzer
Cloudy and Stinks  Yeast
Dissolves  go to pH test
Does not Dissolve  go to iodine test

7. Prep - Powders Dissolved  pH test Acid  Vitamin C Base  add vinegar
Bubbles  Baking Soda
No Bubbles Sodium Acetate
Neutral  observe the crystals
Cubic  Salt
Hex  Sugar

8. Prep - Powders Did Not Dissolved  Iodine test No Change  Sand
Brown / Tan  add vinegar
Bubbles  Calcium Carbonate
No Bubbles Calcium Sulfate
Blue  observe original color
White  Cornstarch
Off-White  Flour

9. Prep - Metals Color Copper Magnet Iron HCl Zinc Tin Aluminum Magnesium
Yellow/Orange
Color
Copper
Other
Attracts
Magnet
Iron
Not
Bubbles; Steam
HCl
Magnesium
Bubbles; No Steam
Zinc
No Bubbles; Dents Easy
Tin
No Bubbles; No Dent
Aluminum

10. Prep - Liquids Physical Characteristics & pH Liquid Odor Color
Blue Litmus
Red Litmus pH
A/B/N
Alcohol
strong
clear R 6 A
Ammonia B
11-12
HydPer
weak to
B to R
Lemon
weak
fruit
yellow 2
Vinegar 3
Water
none 7 N

11. Prep - Hair Human Medullary index < 1/3
even distribution of pigment
Hair Cross-Section
Human Hairs

12. Prep - Hair Animal Medullary index > 1/2 Dog continuous medulla
scales usually not visible
ovoid bodies
root is spade-like

13. Prep - Hair Animal Medullary index > 1/2 Cat
uniserial medulla; very large
spinous scales
root looks frayed

14. Prep - Fibers Animal (Hair) Synthetic cuticle and/or madula
smooth surface
odd cross-section

15. Fiber – Burn Tests Synthetic Animal Vegetable
shrinks from flame or melts
Animal
smolders
smells like burning hair
Vegetable
irregular burn rate
stinks

16. Prep - Polymers Density Dichotomous Key 2 5 4 6 1 Water 46%
Isopropyl Alcohol
Vegetable
Oil
10% NaCl
Saturated
NaCl PP
LDPE
HDPE PS
PETE
PVC PC
PMMA
Unknown Polymer
floats
sinks 2 5 4 6 1

17. Prep - Chromatography
Typical chromatograms

18. Optional - Fingerprints
arch
tented
loop
radial
ulnar

19. Optional - Fingerprints
whorl
central
pocket
double
loop
accidental

20. Optional – DNA Chromatogram

21. Optional - Foot & Tire Prints
visual comparison

22. Optional - Spatter
Directionality
Angle of Impact
Droplet Size

23. Option – Soils compare composition microscopic examination
soil triangle

24. Science Olympiad Crime Busters (B)
Hints, Tips, Things to Prep