Is iron at 101 degrees celsius a solid liquid gas or plasma?
Iron would definitely still be a solid. Water begins to boil at only 100 degrees celsius so there for it would take a much higher temperature to even begin to melt iron.
This is a strange question. Water boils usually at 100 degrees Celsius and freezes at 0 degrees Celsius. Who understands this question? I think you mean "If a substance changes from solid to liquid when the temperature exceeds 100 degrees, will it change from liquid back to solid when cooled to below 100?" Yes, it will.
No, mercury does not become solid in hot temperature and liquid in coolest temperature. But mercury becomes gas or liquid in hot temperature and becomes solid in coolest temperature. Mercury becomes solid after freezing point of -38.72 degrees Celsius. Solid Mercury can become superconductor in reaching of its critical temperature 4.2 K. Mercury is liquid under the room temperature (25 degrees Celsius). Mercury becomes gas after boiling point of 357 degrees Celsius.
It depends on how hot you get it. Iron is a solid almost all the time. If you take it up over 1510 degrees Celsius, it becomes an extremely thick liquid. If you take it over 2750 degrees Celsius, it will turn into a gas. You would only do this if you were cutting it with a plasma cutter, acetylene torch or antitank missile.