Question

tectonic plates moving is what creates mountains and earthquakes

• what layer do tectonic plates move on top of, and what is its physical state?

Explanation:

Tectonic plates move on the asthenosphere. The asthenosphere is part of the Earth's mantle, located beneath the lithosphere (where tectonic plates are). The physical state of the asthenosphere is semi - fluid or plastic - like (it behaves like a viscous fluid over long geological time scales, allowing the rigid tectonic plates to move on it).

Answer:

Tectonic plates move on the asthenosphere, and the asthenosphere is in a semi - fluid (plastic - like) physical state.