Uses of X-rays
In art: detecting covered paintings
In engineering: checking metal castings for defects and crystal analysis
In medicine: there are two main areas
(a) diagnostic. The detection of a broken bone or a tooth cavity
(b) theraputic. The treatment of malignant cancers

Properties of X-rays
(a) they pass through many materials more or less unchanged
(b) they cause fluorescence in materials such as rock salt
(c) they affect photographic plates, causing fogging
(d) they cannot be refracted
(e) they are unaffected by electric and magnetic fields
(f) they discharge electrified bodies by ionising the surrounding air
(g) they can cause photoelectric emission
(h) they are produced when a beam of high-energy electrons strike a metal target