1. The problem statement, all variables and given/known data First-order Bragg diffraction is observed at 25.9degrees relative to the crystal surface, with spacing between atoms of 0.26 nm. a)What is the wavelength of the X-rays? b)At what angle will second order be observed? 2. Relevant equations m[tex]\lambda[/tex]=2dsin[tex]\phi[/tex] 3. The attempt at a solution I solved part b: [tex]\lambda[/tex]=(2dsin[tex]\phi[/tex])=(2(.26*10^-9 m)(sin25.9deg)=.23nm which is correct. For part a I tried: sin[tex]\phi[/tex]=(m[tex]\lambda[/tex])/(2d)=((2)(.23*10^-9 m))/((2)(.26*10^-9))=62.2 Which is apparently close because mastering physics says,"Not quite. Check through your calculations; you may have made a rounding error or used the wrong number of significant figures." Please help! I am down to one attempt and need to get it right this time. Thx!