Question: how long does it take for mercury to change from solid to liquid?

Angus Cook answered on 19 Jun 2016:

For mercury to be solid it needs to be cooler than -40 degrees C.
(in Fahrenheit this is also -40 degrees. It’s the only time that the two temperature scales cross over).
So for it to change from liquid to solid it needs to be taken from below -40 degrees, to above -40 degrees.

The time it takes for this to happen really depends on how quickly you can make the temperature change. You can think of it a bit like water changing from a solid (ice) to a liquid. If you leave an ice-cube in a room on the table, it might take about 4-5 minutes to melt completely. If you hold it over a candle flame though, it’ll take much less time. The same is true of mercury, it’ll melt much quicker in an oven (for example) than an ice-box.

I found this video which might give you an idea of melting mercury to room temperature:

They said that they froze it in liquid nitrogen first, so it’s going from -200 degrees C (it’s important this time) to about 20 degrees (though they don’t say what temperature the water bath is, so could be warmer).