Metals:

* Many metals are gray solids at room temperature, such as iron, silver, lead, and platinum.

Nonmetals:

* Some nonmetals are also gray solids at room temperature, such as carbon (in the form of graphite) and phosphorus (in the form of black phosphorus).

Examples:

* Iron: A silvery-gray metal.

* Graphite: A gray nonmetal used in pencils.

* Black phosphorus: A gray nonmetal used in electronics.

Conclusion:

Therefore, the statement that only metals or only nonmetals are gray solids at room temperature is incorrect. Both groups can have elements that are gray solids at room temperature.