Spectroscopy Measurements of diffraction angle for 1st and 2nd orders of diffraction for yellow sodium doublet

Question

telescope reading

left (1st order of diffraction) 32.3 degrees

(2nd order) 7.8degrees

right (1st order) 73.9degrees

(2nd order) 98.5degrees

double angle (for 1st and 2nd order)???

angle of diffraction (for 1st and 2nd order)???

sine of angle of diffraction (for 1st and 2nd order)???

calculated grating spacing d/nm (for 1st and 2nd order)???

a)calculate all missing values and 2 values of grating spacing for grating students used in the experiment

b)explain why the the angle between the left and right angles from the telescope readings is double the angle of diffraction

Students were told their value for the 2nd order grating spacing was more precise than the 1st order diffraction, so were told to use 2nd order value of d in future calculations

d) calculate numerical value of 1/d and report units

e) explain what this parameter (1/d) tells us about the lines on their grating

Answer 1

7.75