Here's why:
* Mercury's Boiling Point: Mercury has a boiling point of 356.73 °C (674.11 °F).
* Above Boiling Point: 1000 °C is significantly higher than mercury's boiling point.
* State Change: When a substance is heated above its boiling point, it changes from a liquid to a gas.
Therefore, mercury would be in a gaseous state at 1000 °C.