Here's why:

* Nonmetals generally have weaker interatomic forces: This means the atoms are not strongly attracted to each other, making it easier for them to exist as gases where atoms are far apart.

* Examples: Think of the common nonmetals like oxygen (O2), nitrogen (N2), chlorine (Cl2), and hydrogen (H2). These are all gases at room temperature.

However, it's important to remember:

* Some nonmetals are solids at room temperature: Examples include carbon (C), phosphorus (P), sulfur (S), selenium (Se), and iodine (I2).

* One nonmetal is a liquid at room temperature: That's bromine (Br2).

So, while the majority of nonmetals are gases, it's not a universal rule.