Grade 6
2011
Density Rocks
Performance Task for Mini-Unit on Density (could be used in conjunction with unit on
Geology)
Teacher Background
Content Standards:
Physical Science EU 1: Students will understand that all objects and substances are composed
of matter with physical and chemical properties.
Essential Question: How can characteristic properties be used to distinguish one form of
matter to another?
6-8 EU: Matter is classified according to its physical and chemical properties (boiling point,
melting point, density).
Know: Density is a physical property of matter that can be measured and quantified.
Do: Measure and compare the density of objects with either the same or different mass or
volume.
Inquiry Standards:
1.2 PreK-12 EU: Students will understand that identifying questions and concepts will guide
scientific research.
PreK-12 EQ: How are scientific questions formulated?
6-8 EU: Refine, refocus and identify testable questions.
1.3 PreK-12 EU: Students will understand how to design and conduct an investigation.
Investigations are logically organized and use appropriate tools to gather, organize,
represent, and summarize data.
PreK-12 EQ: In what ways can we design and conduct an investigation to test the question?
What evidence is necessary to answer a question?
6-8 EU: Design and conduct a scientific investigation related to the question and hypothesis
that identifies the dependent and independent control variables , uses a control, uses
accurate measurement, collects, quantifies and organizes results, and clarifies ideas based
on scientific knowledge. Students will be able to identify appropriate evidence that will
support or refute a hypothesis.
Grade 6
2011
1.4 Pre-K-12 EU: Students will understand that evidence must be used to analyze and interpret
data and develop conclusions about a hypothesis.
Students will understand it is necessary to communicate scientific findings and be able to
generate further questions.
Students will understand that scientific knowledge gained through investigations can be
transferred to other contexts and applied to real world situations.
PreK-12 EQ: How does your data guide your analysis of an investigation?
To what extent does you evidence support or refute a hypothesis?
How do scientists apply their findings to the real world?
6-8 EU: Explains data, interpretations, and conclusions. Generates new questions to obtain
additional information.
Task:
Students will experiment with different sizes of the same material to determine the density
of an irregular shaped object. Size doesn’t matter if it is the same material the density will
remain the same.
Materials List:
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Scales
Graduated cylinders
Beakers
Water
Quartz rocks of different sizes (may use another material of different sizes with irregular
shapes)
 Calculator
 Science notebook
 Pencil
Administrations:
Prerequisite: This is an assessment to use at or near the end of a unit on density.
Students need a lot of experience relating the question to the problem, including cause and
effect in the question, and planning an investigation.
Grade 6
2011
Students should have knowledge of designing and setting up a data table and / or creating an
accurate scientific drawing
Students need to have many experiences with displacement of water.
Students need to be familiar with and have a lot of practice with the concepts of measuring
mass and volume. They also need to know how to find density using mass and volume.
Students need to have had discussions as to why density is important and how it can relate to
the real world. Examples: In order to be able to float, a body needs to be less dense than
water. Ocean currents are moving due to different water densities and air currents are moving
due to different air densities. Even though water and air are the same materials, the
temperature difference affects the density. (Water temperature at the bottom of lakes or
oceans is colder and therefore, more dense.)
Suggestions:
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Materials need to be out and available to students before the assessment.
Through trial and error, students will find that the beaker cannot be filled to the top or it
will overflow and not be measurable.
Students need to have prior knowledge on using a scale.
Familiarity with vocabulary…mass, volume, density, water displacement, hypothesis,
cause and effect, data, variable, independent variable, control etc.
Teacher Notes:
Grade 6
2011