If inner core is so hot so why it is in solid form?
Answers
... The inner core is solid because it is made of very dense, or heavy, materials - like iron and nickel. Even though it is very hot, these materials don't "melt" very easily, so they stay solid. Answer 3: It turns out that many materials can be a solid at a higher temperature if the pressure is also higher.
At normal temperatures, that cube structure is unstable, and its atomic "planes" easily slide out of the structure into a liquid state. But in the extremes of the core, atoms are moving so quickly, so close together, that they don't have anywhere to go. Like passengers on a packed subway car, they just switch positions but maintain their original shape.
"The sliding of these planes is a bit like shuffling a deck of cards," co-author Anatoly Belonoshko explains. "Even though the cards are put in different positions, the deck is still a deck. Likewise, the BCC iron retains its cubic structure."