The Earth’s core is molten because of the following three main factors:

• Radioactive decay: The Earth’s core contains a significant amount of radioactive elements, such as uranium, thorium, and potassium. These elements release heat as they decay, which helps to keep the core molten.
• Leftover heat from planetary formation: When the Earth formed, it was a very hot ball of material. The heat from this process has not yet dissipated, and it continues to contribute to the heat of the core.
• Frictional heating: The Earth’s core is constantly moving, and this movement causes friction. The frictional heat generated by this movement also helps to keep the core molten.

The molten core is important for several reasons. It helps to generate the Earth’s magnetic field, which protects us from harmful solar radiation. It also helps to drive the convection currents in the mantle, which are responsible for the movement of tectonic plates.

If the Earth did not have a molten core, it would not have a magnetic field. This would expose us to harmful solar radiation, which could damage our DNA and cause health problems. The Earth’s tectonic plates would also not move, which would lead to a much different geological landscape.

In short, the Earth’s molten core is essential for life on Earth. It helps to protect us from harmful radiation and drives the movement of tectonic plates. Without a molten core, the Earth would be a very different place.