Is the outer core denser than the mantle?

The mantle is hotter by a few degrees."The inner core and crust are solid; the outer core and mantle layers are plastic or semi-fluid. The various layers are separated by discontinuities which are evident in SEISMIC DATA; the best known of these is the Mohorovicic discontinuity between the crust and upper mantle."

"The core is probably composed mostly of iron (or nickel/iron) though it is possible that some lighter elements may be present, too. Temperatures at the center of the core may be as high as 7500 K, hotter than the surface of the Sun. The lower mantle is probably mostly silicon, magnesium and oxygen with some iron, calcium and aluminum. The upper mantle is mostly olivene and pyroxene (iron/magnesium silicates), calcium and aluminum. We know most of this only from SEISMIC TECHNIQUES; samples from the upper mantle arrive at the surface as lava from VOLCANOES but the majority of the Earth is inaccessible. The crust is primarily quartz (silicon dioxide) and other silicates like feldspar."