Answer:
In the equation for the critical angle, "n2" represents the refractive index of the medium the light is entering into (the second medium).
Explanation:
The critical angle is the angle of incidence at which light, instead of refracting through a boundary, undergoes total internal reflection within the first medium when it encounters the boundary with the second medium. This phenomenon occurs when the angle of incidence is greater than the critical angle, and it depends on the refractive indices of the two media.