State an example of gas in solid colloidal solution

Explanation:
Colloidal solution of "gas in solid" type is termed solid foam, where dispersion medium(equivalent to solvent)is solid while dispersed phase(equivalent to solute) is gas.
Examples of such solid-foam colloidal systems include pumice stone(a type of igneous rock) , rubber foams, etc.
 
Final Answer:
Hence,an example of (g)/(s)colloidal solution is pumice stone, a type of igneous rock.