Why the inner core of the earth is solid while the outer core is liquid.explain ?

The inner core of the Earth is solid because of the immense pressure that exists at the center of the planet. The pressure at the core is so high that it prevents the iron and nickel in the inner core from melting, despite the extremely high temperatures present. This is known as the solidus temperature, which is the temperature at which a material becomes solid under high pressure.

On the other hand, the outer core is liquid because the pressure is not as high as in the inner core. This allows the iron and nickel in the outer core to remain in a liquid state, even though the temperatures are still very high. The liquid outer core is responsible for generating the Earth's magnetic field through the movement of molten metal, which creates electric currents that produce the magnetic field.

In summary, the solid inner core and liquid outer core of the Earth are a result of the combination of high pressure and temperature conditions at different depths within the planet.