a ray diagram is shown. what does θ₂ represent? index of refraction index of reflection angle of incidence…

Brief Explanations:

In optics, when a ray of light passes from one medium with refractive - index $n_1$ to another medium with refractive - index $n_2$, $\theta_1$ is the angle of incidence (the angle between the incident ray and the normal to the interface) and $\theta_2$ is the angle between the refracted ray and the normal to the interface, which is defined as the angle of refraction. The index of refraction is represented by $n$, and there is no such thing as an "index of reflection" in the context of this ray - diagram.

Answer:

angle of refraction