(a) Name the high energetic invisible electromagnetic wave which helps in the study of the structure of crystals.

(b) State one more use of the wave named in part (a).

State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of visible spectrum.

Name the region just beyond (i) the red end and (ii) the violet end, of the spectrum.

Name the radiation which can be detected by (a) a thermopile (b) a solution of silver chloride.