# If element A floats when placed in element B what can you deduce about the elements?

$\text{(i) that element A is less dense than element B}$.............and given room temperature and pressure.........
$\text{(ii) that element B is probably mercury.}$
There are not that many elemental liquids; there is mercury, and there is also bromine, $B {r}_{2}$. Since bromine is one of the most corrosive substances you can find in a lab, I doubt you would be doing experiments with this noxious substance. You really wouldn't do experiments with mercury either, but it's just possible. Most elements placed in a dish of mercury would float.