Silicates of \(\text{Cu}\) and \(\text{Fe}\)
Copper matte is primarily composed of copper and iron sulphides. It is obtained during the process of smelting copper ores. The smelting process involves heating copper ores in the presence of a flux to separate impurities. The resultant mixture, known as matte, typically contains copper and iron in the form of their sulphides (\(\text{Cu}_2\text{S}\) and \(\text{FeS}\)).
Two soap bubbles of radius 2 cm and 4 cm, respectively, are in contact with each other. The radius of curvature of the common surface, in cm, is _______________.