How can the number of molecules and atoms be the same in a gas? A sample of certain mass of gas was collected and it was found that the number of atoms and the number of molecules in the collected sample are equal. You are required to state the conclusion drawn from this observation.


I am not sure of the answer. I think it is related to the quantity of a mole being constant.
The gas was one (or a mixture) of the noble gases, as every other gas is composed of more atoms than molecules.

Example


Helium: $1~\text{mol}~\ce{He}~\text{gas} = 1~\text{mol}~\ce{He}~\text{atoms}$
Nitrogen: $1~\text{mol}~\ce{N2}~\text{gas} = 2~\text{mol}~\ce{N}~\text{atoms}$