ACT Science 2.4 Research Summary Passage

What is a possible explanation for this amazing phenomenon?

And here are the potential answers…

What’s this question asking?

Well, we have to figure out what mistakes the student made.

Awesome. We have plenty of experience making mistakes. Should be easy to recognize.

So… when was this student’s “Oh shoot” moment… the one that each of us has when

we realize we’ve locked ourselves out of the house?

Well, this student’s moment wasn’t quite so drastic…it was probably around the time

she saw that her filter paper had failed and none of the salt was left on the paper.

But why did this happen?

Well, if she had paid as much attention as we did while reading the procedure,

she would have seen the sentences:

“If the mixture contains a liquid, one technique is to pass the mixture over a filter.”

“This step will remove any components of a mixture that are not dissolved in the aqueous mixture.”

Hmm, this step will remove components that are NOT dissolved.

NOT dissolved, not dissolved…what’s the problem?

Oh yeah! Salt dissolves in water, which means the crystals can’t be separated

from each other with plain ol’ filter.

No, salt and water have a deeper connection than that…it’ll take a lot more to separate them…

A distillation chamber might do the trick, though.

So the filter paper separates sand and water, and the distillation chamber

separates salt and water.

The student didn’t do anything wrong.

Turns out her ‘oh shoot’ moment wasn’t even necessary.

Looks like A is the right answer.

Oh shoot…