Based on my observations in the Sim, I think:
a. Sample 1 and sample 2 are (check one)
* the same substance with the same properties.
1 different substances with different properties.
b. Sample 1 and sample 3 are (check one)
the same substance with the same properties.
• different substances with different properties.
c. Sample 2 and sample 3 are (check one)
the same substance with the same properties.
_ different substances with different properties.