A plate is filled with a layer of water and a lit candle is placed in the centre. A cup is overturned and placed to fully cover the candle. The flame is extinguished, and the cup seems to 'drink the liquid' — the water is sucked from the plate into the cup.
[Figure: Shows experimental setup with candle, cup, and water]
Recall that PV = nRT. Which of the following explains why the cup sucks up the liquid?
a) T decreases so V decreases
b) P decreases so V decreases
c) n decreases so V decreases
d) n decreases so P decreases
e) T decreases so P decreases