Question

Which word best describes the hot, weak, inner part of the upper mantle, which can flow?

Answer 1

asthenosphere

Step-by-step explanation:

The asthenosphere is solid upper mantle material that is so hot that it behaves plastically and can flow. The lithosphere rides on the asthenosphere.

Answer 2

Not sure about single word, but you could describe it as, "The mantle is composed of very hot, dense rock and has the ability to flow like asphalt under a heavy weight." Hope this helps!