Here's why:

* Boiling Point: Liquid nitrogen has a boiling point of -195.8°C (-320.4°F). This means it will turn into a gas at temperatures above this point.

* Room Temperature: Room temperature is typically around 20-25°C (68-77°F). This is significantly higher than liquid nitrogen's boiling point.

Therefore, when exposed to room temperature, liquid nitrogen rapidly boils and evaporates into gaseous nitrogen.