1. Diffraction http:// www.youtube.com/watch?v =a_qRKjeam5w

3. Spectra The burning salt on the knife in the candle shows up orange on the line spectra

4. Diffraction Grating Equation d sin θ = n λ d = distance between the slits Θ = angle to maxima n = integer number to next bright fringe λ = wavelength of light Number of slits per metre N = 1/d Sin θ can never be greater than 1, so there is a limit to the number of spectra that can be obtained.

5. d sin θ = n λ Red light will be seen at d = 1600nm λ = 600nm n = 1 sin θ = (1)*600nm/1600nm = 0.375 θ = sin -1 (0.375) = 22° If you used a DVD then θ would be 47.6°

7. Grating answers d sin θ = n λ 3.

8. Grating answers 4.

9. Diffraction through a single slit The middle fringe is twice the width of all the other fringes. The outer fringes are less intense than the first fringe (W) Width of the central fringe W =( λ a ) x D λ = wavelength a = width of single slit D= distance to the screen

10. The distance between the fringes (w) w