Is mantle a plasma, liquid or solid?
Mantle is mostly solid and comprises mainly igneous but granitic rocks. There is no plasma in mantle.
Mantle is in-between crust and core. It is about 1800 miles thick, Mantle exists only in the rocky planets It accounts for a major portion of the Earth , by volume. Mid-ocean ridges expose mantle. Mercury, Venus, Earth and Mars, and in rocky moons like Luna.