Answer to Question #295215 in Optics for Chemistry

Question

A spherical air bubble in water can function as a lens. Is it a converging or diverging lens? How is its focal length related to its radius?

Answer 1

As the light initially travels from denser medium (water) to rarer medium (air) that is inside the bubble, the light will diverge inside and after that again light continue from rarer to denser and come outside with slightly diverge as compared to the initial one.

thus, the net effect is a divergent ray after coming out from the air bubble and hence it is a diverging lens.