Gold (Aurum, Au) is a chemical element side subgroups of group I of the periodic system of D. I. Mendeleev. Serial number 79, atomic mass (weight) - 196,967. In the connections of the gold one or trivalent. In the tissues and blood of some living organisms is up to 14 mg/kg of gold.
gold Gold is malleable metal of yellow color, density 19,3, temperature melting 1063 degrees.
Chemically gold light (gold belongs to the so-called noble metals), in air is not oxidized, acids and alkalis not soluble, soluble in Aqua Regia; with mercury forms amalgams. Metallic gold is used in dental practice.
From artificially obtained radioactive isotope of gold in medicine apply Au198 with a half-life of 2.7 days and Au199 with a half-life of 3.1 days. Both of these isotopes are weak beta-emitters (see Beta-radiation), but also possess and gamma rays (see). Radioactive gold used in radioisotope diagnostics (see)and radiation therapy (see). With colloidal Au198 spend lymph radiography (see). It is also used intravenously in the treatment of leukemia, for introduction into the chest or abdominal cavity, for direct entry into the tumor.
Of radioactive gold prepare needles for injections tumors, as well as grain for the introduction of natural cavity (see Radioactive drugs). As used drugs radioactive gold have gamma radiation while working with them and their storage should be used with devices for protection from radiation - containers for solutions, syringes with special shields, etc.
Cm. also Antiradiation protection, Radiological Department.