Science
Strand IV
Use Scientific Knowledge from the Physical Sciences in Real-World Contexts

 

Science/Strand IV
Content Standard 2
All students will investigate, describe, and analyze ways in which matter changes; describe how living things and human technology change matter and transform energy; explain how visible changes in matter are related to atoms and molecules; and how changes in matter are related to changes in energy. (Changes in Matter)

 

Science/Strand IV/Content Standard 2
High School

 

Science/Strand IV/Content Standard 2/High School
Benchmark 2
Explain why mass is conserved in physical and chemical changes.

Benchmark Clarification

Because atoms are not created or destroyed during physical changes and chemical changes, the mass of material before the change is equal to the mass after the change.

See Physical changes (SCI.IV.2.MS.3).

See Chemical changes (SCI.IV.2.HS.4).

Students will:

  • Recognize that the mass before and after physical and chemical changes is equal
  • Explain how the number and kinds of atoms before the changes are the same as after the changes

Key Concept / Real World Context / Instructional Example / Assessment Example / Resources

 

Science/Strand IV/Content Standard 2/High School/Benchmark 2
Key Concept

  • atom
  • molecule
  • mass

 

Science/Strand IV/Content Standard 2/High School/Benchmark 2
Real World Context
Common physical and chemical changes including matter cycles in ecosystems

 

Science/Strand IV/Content Standard 2/High School/Benchmark 2
Instructional Example

Benchmark Question: How does matter change?

Focus Question: How is mass conserved in physical and chemical changes?

Students will perform a chemical change and a physical change in small lab groups. They will weigh and compare the masses of reactants and products in each case. Working in these same small groups, students will write summaries comparing the masses of products and reactants. Groups will share their summaries with the class.

Changes might include the following: Physical change: Melting ice cube, tearing paper, breaking beaker.

Chemical change: Burning, rusting, forming a precipitate. See (SCI.IV.2.HS.1).

Constructing: (SCI.I.1HS.1), (SCI.I.1.HS.2), (SCI.I.1HS.3)

Reflecting: (SCI.II.1HS.3).

 

Science/Strand IV/Content Standard 2/High School/Benchmark 2
Assessment Example

Given the mass data of reactants, students will predict the total mass of the products and explain the prediction by using the concept of conservation of mass.

(Give students rubric before activity.)

Scoring Rubric

Criteria

Apprentice

Basic

Meets

Exceeds

Accuracy of prediction

Gives incorrect prediction of total mass.

Gives correct prediction of total mass.

Gives correct prediction of total mass that relates to explanation.

Gives correct prediction of total mass that relates to explanation and a description of what is happening at the atomic level.

Correctness of explanation

Gives incorrect explanation of conservation of matter with many misconceptions.

Gives correct explanation of conservation of matter with some misconceptions.

Gives correct explanation of conservation of matter with a few misconceptions.

Gives correct explanation of conservation of matter with no misconceptions.

 

Science/Strand IV/Content Standard 2/High School/Benchmark 2
Resources

Webliography.
http://mtn.merit.edu/mcf/SCI.IV.2.HS.2.html

Conservation.
http://tqd.advanced.org/3042/conservation.html