Who killed the fish in the science lab? page 1

Science Crime Busters

School Name:______

Team #:______

Individual Names:______

______

Circle one: VarsityJV

Total Score:______

On Monday morning, March 1st,Mrs. Creek, the head science teacherof Jefferson Middle School arrived at her classroom to prepare for Monday’s classes. Upon her arrival, she stopped to feed the lab’s fish and found 10 large-mouth bass floating at the top of the tank. She knew that her sixth group students would be devastated that they would not be able to release their bass into the wild that spring. The bass tank appeared untouched at first, though upon closer inspection she noticed that the light bulb was broken and shards of glass were floating in the tank. Taped to the side of the tank was a note that said, “I’m sorry!” She also noticed that her supply cabinet had been broken into and that drops of dried liquid were scattered in a trail from the cabinet to the bass tank. Because the loss of her class’ fish was a big deal, the science teacher called her principal to help determine who killed the fish. When the principal arrived, he made a list of the rest of the details found at the scene.

  • A set of muddy shoe prints into the room and up to the tank
  • A spatter of human blood on the floorand the side of the light fixture of the tank
  • Matching fingerprints on the glass tank and the broken supply closet
  • Nothing was inoperable on the tank except for the broken light bulb.
  • Powder residue found around the tank

Being the head science teacher with many years of experience, she felt optimistic that she could use the power of scientific evidence to help her solve this crime. So, the science teacher asked many of the other teachers and coaches around school if they saw anybody suspicious around the lab between last Friday evening and this Monday morning. She was told that on Friday night there had been basketball practice and art club until 5:00 p.m. Unfortunately, she had left by 4:00 p.m. on Friday for a doctor’s appointment. On Saturday morning, the Olympiad team and coachstopped at school to load up their supplies and catch a bus to their regional competition.

After questioning several witnesses the principaland the science teacher narrowed their investigation to five key suspects.

  1. Samantha Smelt: Ms. Smelt is the quiet, lovable second science teacher at Jefferson Middle School. She is also the new coach of the science Olympiad team. She knows that a win at the regional competition could earn her the respect she feels she deserves. Ms. Smelt spends many hours at school on weeknights and weekends preparing lessons. Ms. Smelt has a variety of pens sitting in a beaker on her desk. She was likely at the lab on Saturday morning preparing for the Olympiad competition, and though she usually dresses very professionally during the week, she does not need to dress up for the competition. Lately she has been feeling sick to her stomach and so she called in sick on Monday.
  2. Mickey Muskie: Mickey is the jolly, overworked janitor at Jefferson Middle School who often injures himself on the job. He is very tired and sometimes can be found sleeping at his desk. He has been heard telling other staff members that he was going to have to do something drastic if the school didn’t hire an assistant soon. He is often asked to care for the fish when the science teacher is away. Mickey typically wears a pair of coveralls and boots to protect his clothing and body from harsh chemicals.

  1. Peter Pike: Peter is a star member of the Jefferson Middle School basketball team and was seen hanging out around the school grounds late after practice Friday night. He is still furious about having to forfeit an important conference game because other members of the team were busy at a science competition. He is frequently injured because of rough play during games and practices. He has been warned that he will be cut from the team if his behavior continues. A pen was found on the ledge near his gym locker. Peter would likely still be wearing gym shoes after practice on Friday night.
  1. Tommy Trout: Tommy was cut from the basketball team this week because he is failing biology. He also recently destroyed a $300.00 microscope because he was showing off by carrying it over his head. Tommy’s parents suspended his allowance and grounded him for a month. Despite that, Tommy was seen hanging out with his girlfriend early Saturday morning at Denny’s. He had a large gash on his cheek, a pen in his shirt pocket, and his usual fistful of salted pretzels. Tommy usually wears gym shoes.
  2. Sally Sunfish: Sally is the petite, meticulous president of the Jefferson Middle School art club, who often complains that the science Olympiad club always gets tons of snacks at their meetings and claims that art club membership is down due to an increased interest in Science Olympiad. She has a pencil case full of art pens and access to chemicals in the photo lab. She frequently walks past the science labs to get to the kiln and was found with a bandage on her knuckle from a purported paper cut. Her art specialty is clothing design, and her classmates claim they can hear her coming a mile away between her fancy shoes and clunky jewelry.

  1. UNKNOWN SUBSTANCE ANALYSIS: (51 points)

Identify all unknowns correctly.

List of Possible Unknowns

Non-Powdered Metals / Solids / Liquids
Aluminum / Salt (NACl) / Sodium Acetate / Rubbing Alcohol
Iron / Sugar / Sand / Ammonia (3%)
Tin / Flour / Powdered Gelatin / Water
Zinc / Gypsum / Yeast / Vinegar
Copper / Corn Starch / Vitamin C / Hydrogen Peroxide
Magnesium / Calcium Carbonate / Baking Soda / Lemon Juice
Powdered Alka-Seltzer

SUBSTANCE #1______SUBSTANCE#9______

______

SUBSTANCE #2______SUBSTANCE #10______

SUBSTANCE #3______SUBSTANCE #11______

SUBSTANCE #4______SUBSTANCE #12______

SUBSTANCE #5______SUBSTANCE #13______

SUBSTANCE #6______SUBSTANCE #14______

SUBSTANCE #7______SUBSTANCE #15______

SUBSTANCE #8______

NOTE:

  • Substances #1 & #9 are mixtures.
  • These substances were found at the scene of the crime: #5, #6, #7, #11, #14, #15
  1. SHOEPRINTS: (2 points)

Evidence AEvidence B

Based upon the evidence of what each individual was wearing, whose shoeprints were found at the crime scene?(See suspect files.)

Evidence A:Evidence B:

  1. FINGERPRINTS: (6 points)

AB

The tank and the cabinet were brushed for fingerprints.

Crime scene evidence:

Whose fingerprints were found at the crime scene? (See suspect files.)

Label the each print as whorl, loop, or arch

Fingerprint A(suspect)______Fingerprint B(suspect)______

Type of print:A:______B:______

IV.CHROMATOGRAPHY: (5 points)

Perform a chromatography test on each of the pens found in the possession of the suspects.

Identify the suspect/s whose pen matches that of the one used to write the message found in coach’s office on the line below.

Chromatogram of ink found on note:

Tape your chromatography strips below:

V: WATER QUALITY: (9 points)

Test for cause of death:

  • Dissolved oxygen
  • Chlorine poisoning
  • Change in pH

Cause of death:

VI: DNA ANALYSIS: (2 points)

Whose DNA matches the blood found at the crime scene? (See suspect files.)

______

VII: WRITTEN ANALYSIS: (25 points)

Based on the evidence you collected, explain who committed the crime and why.