That depends on what you're talking about! "Room temperature" is usually considered to be around 20-25 degrees Celsius (68-77 degrees Fahrenheit).

Here are the states of matter of some common substances at room temperature:

* Solid: Ice, rocks, wood, metal

* Liquid: Water, oil, juice, mercury

* Gas: Air (nitrogen, oxygen, etc.), helium, carbon dioxide

There are also some substances that are in a state of matter called a plasma at room temperature, but this is less common.