The product's price decreases.
I hope that helps!
The pressure on the inner core is greater than on the outer core and the melting point of iron, and because the pressure effect is higher than the temperature effect, the inner core is solidified.
Based on the information I was able to find I would say "Natural gases".
This is due to the reason it is burned to create heat for buildings which are used for several things we do daily such as cooking, heating, and electricity.
