<human>:  Can you transport a coin along a sea of mercury?
<bot>: Yes, you can transport a coin along a sea of mercury. The density of an object determines if it will float. An object will float if it is less dense than the liquid it is placed in. Mercury is liquid at room temperature. The density of mercury is 13.56 g/cm3. The density of a penny is 7.15 g/cm3, so it will float.