In which of the following, interface can not be obtained?
Liquid-Liquid
Liquid-Gas
Solid-Liquid
Gas-Gas
In the physical sciences, an interface is a boundary between two spatial regions occupied by different matter, or by matter in different physical states. The interface between matter and air, or matter and vacuum, is called a surface, and studied in surface science.
The gas- gas mixture is homogeneous due to complete miscibility, there is no interface/boundary that can be obtain between the gases.
Therefore, Option(4) is correct