Writing a Scientific Argument When you write your scientific argument to Dr. Flores:
Choose only 1 claim, not all 3 of them. Remember to explain how your evidence supports or refutes the claim you selected and why your evidence is significant.
Use the sentence starters below to help explain your thinking.
Question: Why is the liquid oxygen machine producing less liquid oxygen than normal?
Claim 1: There is frozen water in tank 2, which is blocking some of the oxygen from going into tank 3.
Claim 2: Some of the liquid oxygen evaporated in tank 3.
Claim 3: Some of the oxygen didn’t condense in tank 2.
Reference information from the “Liquid Oxygen” article:
Water has a stronger attraction between molecules than oxygen or nitrogen.
Oxygen has a stronger attraction than nitrogen.
Scientific Argument Sentence Starters
Describing evidence
The evidence that supports (or refutes) my claim is...
My first piece of evidence is...
Another piece of evidence is...
Scientists found...
Explaining how the evidence supports the claim
If, then...
This is important because...
Since...
Based on the evidence, I conclude that...
This claim is stronger (or weaker) because...

Word Bank - All of these words should be used!
energy evaporation freedom of movement freezing
kinetic energy molecule phase change temperature

Writing a Scientific Argument (continued)
Write a scientific argument that answers the question Why is the liquid oxygen machine producing less liquid oxygen than normal?
State your claim and use evidence to support it. For each piece of evidence you use, explain how the evidence supports your claim or refutes another claim. Remember to explain what happened at both the macro and molecular scale.