Biprism experiment D = tm, d - 0.1 cm and band width 0.058 cm, calculate Wavelength of light used.

The figure below depicts spectral reflectance measurements for three different materials:  a green leaf from a healthy plant, a sheet of shiny blue paper, and the palm of a human hand.  The measurements are labeled 1 (black line), 2 (red line), and 3 (blue line).  Match the measurements to the most appropriate material type

3.2 (a) Determine the absorption coefficient for Si illumination form radiation with wavelength equal to 0.5 μm. (b) Calculate the thickness of Si that will absorb 60, 70, 80 and 90% of the photon energy/cm²s

1.2) In a region of gas where the optical depth is 2.0, what percentage of photons can escape without being scattered or absorbed?