I'd say it's suspension, but I'm not 100% sure...
A) eventually they will be in thermal equilibrium
Answer: It is important to wet the filter paper in the Buchner funnel first with cold re crystallization solvent before the re crystallization mixture being filtered to minimize gaps around the edges of the filter paper which can prevent mechanical impurities from passing through. This gives better filtration where most impurities can be filtered. Furthermore, it provides good vacuum.
A beta emission radioactive decay can pass through the body.
