|
Performance Task:
|
|
|
For this task you are to form a team with three
other members of your class to work as criminal lab technicians for the Department of Justice. Your team has been assigned to
determine the identify of three liquids, red, blue and yellow, taken from a murder crime scene. Prosecution
attorneys believe one or more of the three liquids are poison, while defense attorneys claim they are all
water. Your team must do density tests on the three liquids to determine if they are water or if one or more
are "poison." If the liquid has a density different from that of water, it is "poison."
Using a 100 ml graduated cylinder and a triple-beam balance, design a
procedure to test the densities of water and of your three liquids. Make a drawing of your experimental setup.
Construct a data table and a graphic display of the data your team collects. Write a lab report,
outlining your procedures and findings.
Include your data table and graphs. Make at least one conclusion based on
your data. Compare your results with those of other groups in your class.
Note to the teacher: "Poison" can be made by mixing 3 cups of
sugar per half-gallon of water and adding 1 cup of salt to increase density and prevent fermentation. Food coloring helps increase interest and help
distinguish the liquids.
|
|
Knowledge / Skills:
|
|
|
Know and apply the principles of scientific
inquiry. (s114)
Exhibit good data management skills by
collecting, organizing, and graphing data.
(s19)
Understand the characteristics of density and
how it varies in materials with the change of temperature, pressure, and
phase (gas, liquid, solid). (s22)
Measure properties of the environment using
dimensional quantities such as time, length, mass, pressure, volume,
acceleration, etc. Compare quantities and consider the error involved with
measuring environmental properties.
(s23)
Participate, sometimes leading, in group
meetings by contributing, taking turns speaking, and working toward a
common goal. (ela20)
Use writing as a tool for learning in formats
such as learning logs, laboratory reports, note-taking, and journals. (ela40)
|
|
Rubric:
|
|
|
4 Points =
The students complete the laboratory exercise independently. Their
lab report is neat, thorough and accurate. They reach a conclusion based on
their data and in collaboration with other groups. The students' report
indicates they have an understanding of the concept of density and are able
to apply that knowledge and understanding to a relevant situation. Their
conclusion(s) is drawn from their data and graph and in collaboration with
other groups. The students work cooperatively as a team, performing their own part and being supportive of other team members.
3 Points = The students need some assistance to
complete the laboratory exercise. Their lab report is fairly neat and
accurate, but it lacks good organization which makes it difficult for
others to follow. The students' report indicates they have a fairly good
understanding of the concept of density and that they are able to apply
that knowledge and understanding in a relevant situation. Their conclusion
is drawn
from their data and graphs, but they do not collaborate with other groups.
The students work cooperatively as a team.
2 Points = The students need continual assistance
to complete the laboratory exercise. They do not demonstrate an
independence in conducting a scientific inquiry. The students' data are
sketchy. Hence, the accuracy of their data tables and graphs is
questionable. The lab report is not well presented and it is not clear that
the students really have an understanding of the concept of density. The
conclusion is vague and focuses on the identities of the liquids without
any direct reference to the data tables and/or
graphs. No attempt is made to collaborate with other groups. The students
work more as individuals than as members of a team.
1 Point = Even with sustained assistance, the students are unable to
complete the laboratory exercise. The students lab setup does not
satisfactory collect the data they need. Hence, their data tables and graphs, if constructed, have little meaning. The students show no
understanding of how to conduct this scientific inquiry and indicate little knowledge of the concept of
density. They show no connection of the exercise to real life. The students either reach the wrong
conclusion or are unable to reach any conclusion at all. They make no attempt to collaborate with other groups.
The students do not work cooperatively as a group.
|
