Human: When the Earth was formed, was the core molten? Assistant: 
The Earth’s core is made of a mixture of molten metal and rocky material. The core is made of a fluid mixture of iron, nickel, and sulfur. The core is very hot, and the pressure at the center of the Earth is about 1,200 times greater than the pressure at the surface. The temperature of the core is estimated to be about 4,000 degrees Celsius.