Why is there lava in the core of the Earth?

The crust, mantle and inner core of the earth are all solid rock (or iron in the case of the core). The only large portion of the earth's interior that is liquid is the outer core, and lava does not come from there (again, if it did, it would be molten iron). read more

There is no ‘lava’ inside the Earth. There is ‘Magma’. Lava is the term we use to describe Magma (molten rocks) that flow on the surface of the Earth. Having the confusion of terms out of the way, the inner core of the Earth is actually solid, and not liquid. read more

Since the core is far from the surface, there is no lava there. Also, the inner core is solid and the outer core is liquid, another (quasi) misleading point. The main source of heat is, as another mentioned, radioactive isotopes of uranium, thorium and potassium. read more

There are three main sources of heat in the deep earth: (1) heat from when the planet formed and accreted, which has not yet been lost; (2) frictional heating, caused by denser core material sinking to the center of the planet; and (3) heat from the decay of radioactive elements. read more