Does the Earth's mantle behave like a liquid?

Yes, actual at school we did a project where we used thick molasses and talc powder. Put it in several layers on a backing plate and let it rest for some time. Then put it in an incline and wait for it to slowly sag. read more

However, the mantle is split into an upper and lower zone which are exposed to vastly different temperatures and pressures. Over millions of years, you see the mantle behave like some sort of plastic, able to have solid crust “flow” on it. read more

In the mantle, this means that on a short time scale (e.g. on the time scale of a seismic wave) it behaves as a solid, but in a longer time scale behaves as a viscous liquid. read more