In a science lab I did recently we placed wax candles into two different liquids to see if they would float or sink. In one liquid, the candle floated, and the other one it sunk. We swapped the candles to confirm it was caused by the difference in the density of the candles and the two liquids. We were given a brief amount of homework on this, of which my question orginated.
The homework question that got me thinking (This is not my question, it's what lead up to it) was asking if there was a limit to how small the candle could be made and still behave the same way in each of the liquids. I considered that if there were two or more molecules, the candle would still have density due to there being an amount of space between them, or a density, and thus behave the same way. However, I am unsure if a single molecule or atom would have a density or not, since it is a single particle in space with actual properties.
So, in simplicity, the question is the title. Does a single molecule/atom have a density to it? Why?