Description:

During this activity the students will work with a lab partner (or possibly two partners). The students must keep their own individual lab notes because after they finish, they will work independently to write a lab report ("article") about the experiment.

This task is designed to take students approximately 45 minutes to complete.

Overall Task Content Area:

Physical Science

Specific Knowledge Areas:

Structure and Properties of Matter

Performance Expectations:

• conducting investigations
• using equipment
• gathering, organizing, and representing data
• formulating conclusions from investigational data
• applying scientific principles to develop explanations and solve new problems

National Science Education Standards:

12 A SI 1: Abilities necessary to do scientific inquiry: Grades 9-12
1.2 Design and conduct scientific investigations. Designing and conducting a scientific investigation requires introduction to the major concepts in the area being investigated, proper equipment, safety precautions, assistance with methodological problems, recommendations for use of technologies, clarification of ideas that guide the inquiry, and scientific knowledge obtained from sources other than the actual investigation. The investigation may also require student clarification of the question, method, controls, and variables; student organization and display of data; student revision of methods and explanations; and a public presentation of the results with a critical response from peers. Regardless of the scientific investigation performed, students must use evidence, apply logic, and construct an argument for their proposed explanations.

1.4 Formulate and revise scientific explanations and models using logic and evidence. Student inquiries should culminate in formulating an explanation or model. Models should be physical, conceptual, and mathematical. In the process of answering the questions, the students should engage in discussions and arguments that result in the revision of their explanations. These discussions should be based on scientific knowledge, the use of logic, and evidence from their investigation.

1.6 Communicate and defend a scientific argument. Students in school science programs should develop the abilities associated with accurate and effective communication. These include writing and following procedures, expressing concepts, reviewing information, summarizing data, using language appropriately, developing diagrams and charts, explaining statistical analysis, speaking clearly and logically, constructing a reasoned argument, and responding appropriately to critical comments.

(Use the "hot" link on the PALS home page to check the full text of related National Science Education Standards, if desired.)

National Council of Teachers of Mathematics:

DAP1: Formulate questions that can be addressed with data and collect, organize, and display relevant data to answer them:
Grades 9-12 j. understand the differences among various kinds of studies and which types of inferences can legitimately be drawn from each
Grades 9-12 l. understand the meaning of measurement data and categorical data, of univariate and bivariate data, and of the term variable

PS1: Build new mathematical knowledge through problem solving:
Grades 9-12

CNX1: Recognize and use connections among mathematical ideas:
Grades 9-12

Materials:

Table salt (approximately 60g)
Rock salt (approximately 60g)
Ice cubes (approximately 500g)
Tap water
Graduated cylinder
Beakers (2)
Paper towels for cleanup
Access to a clock or watch with a second hand
Paper cups (2)
Plastic spoons (2)
Thermometers (2)
Weighing paper (2 sheets)
Access to a balance
Safety equipment
Access to a calculator

Timing

The total time for this task is 45-60 minutes. Students work together designing and performing the task and recording data. They finish the task by working individually to write a lab report in the form of a newspaper article telling citizens which type of salt, if either, is better for melting ice on steps and sidewalks.

Safety:

• Be careful.
• Teachers and students should always exercise appropriate safety precautions and utilize appropriate laboratory safety procedures and equipment when working on science performance tasks.