Why's is Earth's core very hot?
86122
I was taught in school that it is due to radioactive decay of elements in the core.  That is pure bullcrap.  If it were true, every time a volcano exploded, there would be radioactive toxins spread out across the world.  Others say gravity pushing on the substances create heat and liquification of earth.  This may be somewhat true.  If you put a piece of solid ice in a chamber and put extreme pressure on it, it turns to liquid.  There must be some other source of internal heat generation though.  I have never found a satisfactory answer to date.  I really don't think anyone knows, just like gravity is still a big mystery.
509040
The Earth is not Hollow. Below the 60 Km crust is the semi-liquid Mantle. The core at the center is Solid.
507812
There is no way to measure the temperature at the Earth's core directly. near the surface of the Earth, the temperature increases by about 1 degree Fahrenheit for every 60 feet in depth............The interior of the Earth reaches temperatures of 5650 ± 600
710689
It does not help.  It is the LACK of sufficient conduction in the mantle that forces the core to get rid of its heat by mantle convection instead.  If the mantle conducted better, it wouldn't need to convect, and then there would be no plate tectonic movement at all.
751689
The crust and mantle are generally solid.  The inner and outer core are molten rock and metal...very dense, but still liquid.
368743
When the earth formed, it was basically all just really hot rock.  So hot, in fact, that it melted.  When the rock melted, the heavier elements (iron and nickel) sunk towards the core of the earth.  This sinking of heavy elements transferred a lot of gravitational potential energy into heat energy.  The same can be seen today.  If you drop something heavy into a bucket of water, after you drop it enough, the water itself warms up.  This heat energy from the formation of the planet was the primary source of the heat of our planet.  However, another major source of heat today is the breakdown of radioactive elements inside the earth.  Both of these contribute to the heat the Earth generates.
378675
it's estimated at 3000 to 5000 celsius; but there is no precise answer to this since no one has ever really attempted to measure the temperature of the earth's core.
1122546
No, for two reasons.\n\nFirst, the centre of the Earth is under two much pressure and too hot.\n\nSecond, diamonds are made of carbon, which doesn't exist in the centre of the earth. The centre of the earth is solid nickel and iron.
977025
Lord Kelvin back in the 19th Century showed that the Earth would have radiated all its original heat from formation long ago.  He therefore concluded that there must be nuclear processes occurring in the core which keep Earth's interior warm (who said nuclear energy was bad).  When these processes stop, the Earth will cool down.  I don't know (who does) but I expect that this will happen long before our sun's fuel is spent, although there's no need to worry - it won't be any time soon.\n\nIncidentally, it is extraordinary to think that we actually know remarkably little about the processes occurring in the core of the Earth and we have scarcely even scratched the surface in our exploration of our own planet.  We actually know far more about what happens in the core of the sun!
493180
Core.... filled wid liquid metals.... its sooo hot out there...
3355
the earth, in the interior, is very much hot. This heat energy starts to boil the groundwater near it and produces steam.this steam is the geothermal power.
885539
Temperature increases as pressure increases due to increased molecular collisions.  The Earth generates an incredible amount of gravity, meaning that everything is pulled towards the center of the Earth.  So at the center of the Earth is an incredible amount of pressure due to the incredibly high density of molecules moving around there, and thus the temperature is incredibly high!
538992
Earth's core is thought to be made of molten nickel-iron. The core is about 2100 miles in radius, with a temperature of approximately 13,000 degrees Fahrenheit.
179806
At the center of the earth the effects of the increasing pressure (which will cause the ball to implode) are greater than the effects of the increasing temperature (which would make the gases inside the ball expand to such an extent that the ball would explode) so the ball would implode. Studies of the seismic waves from earthquakes travelling through the earth tell us that the very center of the earth's core is actually solid, the hot material crushed into a solid form by the pressure. The outer layers of the core are liquid due to the high temperatures at lower pressure.
300814
the temperature at the inner core of the earth is at the high is about 7,000 degrees Celsius
1150478
It's widely believed in the scientific community that the earth has a liquid mantle (that's where magma/lava comes from) and a solid super-hot iron core.  Good luck digging through that.
273055
This is my guess:\n\nThe hottest temperature is probably when the particles move at almost the speed of light, I don't know what that is though.\n\nTemperatures can be as high as billions of degrees.\n\nHowever, temperature don't necessarily mean how hot it is, at temperatures of billions of degrees, you could still freeze!