The light slows down and bends towards the normal.

The light speeds up and bends away from the normal.

Total internal reflection occurs; the light is completely reflected back into the original medium.

Diffuse reflection occurs, scattering light in many directions.

The angle of refraction increases until it reaches 90 degrees (critical angle), beyond which total internal reflection occurs.

1: Incident Ray, 2: Reflected Ray, 3: Normal Line, 4: Angle of Incidence (θi), 5: Angle of Reflection (θr)

1: Incident Ray, 2: Refracted Ray, 3: Normal Line, 4: Angle of Incidence (θ₁), 5: Angle of Refraction (θ₂)

1: Incident Ray, 2: Refracted Ray (at 90 degrees), 3: Reflected Ray (Total Internal Reflection), 4: Critical Angle (θc)

1. Identify the two media and their indices of refraction (n₁ and n₂). 2. Determine the angle of incidence (θ₁). 3. Use Snell's Law $n_1 \sin(θ_1) = n_2 \sin(θ_2)$ to solve for the angle of refraction (θ₂).

1. Compare the indices of refraction of the two media. 2. If light goes from a lower to a higher index (n₂ > n₁), it bends towards the normal. 3. If light goes from a higher to a lower index (n₂ < n₁), it bends away from the normal.

1. Light must be traveling from a medium with a higher index of refraction (n₁) to a medium with a lower index of refraction (n₂). 2. The angle of incidence (θ₁) must be greater than the critical angle (θc).

1. Identify the indices of refraction of the two media (n₁ and n₂), where n₁ > n₂. 2. Use the formula $\sin(θ_c) = \frac{n_2}{n_1}$ to find the sine of the critical angle. 3. Calculate the critical angle (θc) by taking the inverse sine (arcsin) of the result.

1. Determine the type of interaction: reflection, refraction, or absorption. 2. If reflection, apply the law of reflection. 3. If refraction, use Snell's Law to calculate the angle of refraction. 4. If TIR is possible, check if the angle of incidence exceeds the critical angle.