1. The problem statement, all variables and given/known data A crystal is heated from 0 to 100 degrees celcius, its lattice parameter 'a' increases by 0.17% due to thermal expansion. if we observe an x-ray reflection at a bragg angle theta= 19.3 degrees at 0 degrees celcius, by how much will theta change when the sample is heated to 100 degrees C. (don't need to know wavelength or d to solve) 2. Relevant equations 2dsin(theta) = n[itex]\lambda[/itex] 3. The attempt at a solution Tried using 1 for d. and just seeing how much it'd change but it didn't come out right.