(a) X rays have a wavelength of 50\(\overset{\circ }{\mathop{A}}\,\)
(b) In vacuum, the speed of an electromagnetic wave is \(3\times {{10}^{8}}\) m/s.
(c) Because they are stopped by bones, they are utilised in medical science to identify fractures in bones, teeth, and other soft tissues, as well as for diagnostic purposes such as CAT scan.