Mass and Phase Change Investigation Walkthrough Name:
(This will not be collected or graded but you will need it to write your lab report)
Question that we are investigating: How is the mass of a substance affected when the substance changes phases?
Is this a testable claim? __________
Test #1: Solid to Liquid (Melting)
To test a claim we need to have a measurable independent variable (the thing we are changing).
What will be our independent variable?
We need a measurable dependent variable (the thing that is affected by out changing independent variable).
What will be our dependent variable?
How can we measure the dependent variable?
We also need the make sure there are control variables (everything else that we make sure is stays the same throughout the experiment).
What will be our control variables? How can we make sure that they are kept constant?
Control Variable How to control it
Hypothesis:
What do you believe the outcome of the experiment will be and why do you believe this? (Make sure to include your independent and dependent variable in your hypothesis).
Materials:
What are the materials that someone will need when they redo this experiment?

Procedure:
What is the procedure that someone next year would have to follow in order to redo your experiment exactly?
Test #2: Liquid to Solid (Freezing)
To test a claim we need to have a measurable independent variable (the thing we are changing).
What will be our independent variable?
We need a measurable dependent variable (the thing that is affected by out changing independent variable).
What will be our dependent variable?
How can we measure the dependent variable?
We also need the make sure there are control variables (everything else that we make sure is stays the same throughout the experiment).
What will be our control variables? How can we make sure that they are kept constant?
Control Variable How to control it
Hypothesis:
What do you believe the outcome of the experiment will be and why do you believe this? (Make sure to include your independent and dependent variable in your hypothesis).
Materials:
What are the materials that someone will need when they redo this experiment?

Procedure:
What is the procedure that someone next year would have to follow in order to redo your experiment exactly?
Data:
Make data tables to collect your data for the experiment:
Melting Freezing
Conduct your experiment and fill in your data table above.
Analysis: (We need to wait until after we have collected the data from all classes)
1.
Looking at the data from all classes, are there any outliers for either melting water or freezing water? If so, what are the outliers? Why are they outliers? (Explain using numbers and specific examples from the data)
2.
What may be some reasons why everyone’s data was not exactly the same if everyone did the same procedure? (What were some possible causes of errors? What effect would these errors have on the data?)

3.
After analyzing all of the data and excluding the outliers, what can you conclude about how melting water affects the mass of the water? (Explain why you are making this conclusion based on the data.)
4.
After analyzing all of the data and excluding the outliers, what can you conclude about how freezing water affects the mass of the water? (Explain why you are making this conclusion based on the data.)
5.
Based only on our experiment and our data, can we now definitively say what happens to the mass of a substance when it changes phases? Why or why not?
6.
How would you improve this experiment to obtain more accurate and precise results? (Explain what specific changes could be made and why they would give more accurate and precise results).

CER:
Claim: What claim are you making after conducting the experiment and analyzing the data?
(This is a one or two sentence statement stating your newly tested and researched belief). (Like your hypothesis, your claim needs to include the independent and dependent variable.)
Evidence: Explain what evidence you have collected that makes you sure your claim is correct.
Reasoning: What scientific knowledge or explanations about what you know is happening also backs up your claim? (This is aside from the data collected in the experiment itself).
Hint: think of what mass is. You can refer to past lessons that involved mass, or look up information about mass and how it changes or doesn’t change when changing phases. Make sure to check multiple sources and be sure to cite your sources if you are using any. Wiki answers, google answers, etc are not going to be acceptable sources of information.