∴ 1/3.7 kilo curie = 10¹³ Bq = A. For one mole of radium, the number of atoms = 6.023 × 10²³ = N. Therefore, decay constant. Hope this helps. Still have questions? This Radium Hot Springs resort is situated on 9 beautiful acres of property with peaceful surroundings and incredible landscapes. Each 1, 2, & 3 bedroom suite offers full kitchens, living room, deck or balcony with BBQ, washer & dryer, and stunning mountain or golf course views.
For scientific purposes standards of radium have been made with which any sample of unknown strength may be easily com pared. The comparison is made not by their respective weights but by the intensities of their radiations. Draw io free. The international radium standard was prepared by Mme. Curie and is kept in France at Sevres ; secondary standards, carefully checked with the primary one, are kept in other places, particularly at the Radium Institute, Paris, the National Physical Laboratory, Teddington, England, the Physikalisch-technische Reichsanstalt, Berlin, the Radium Institut, Vienna and at the U.S. Bureau of Standards, Washing ton. The sample to be measured, which should exceed in intensity that of one-tenth of a milligram of pure radium, is sealed up in glass for at least one month, so that what is called the equilibrium quantity of radon and the successive products radium A, B, C and C' have formed. The intensity of the 7-radiation from radium C is then determined by an electrical method under speci fied conditions which need not be detailed. Since there is a con stant ratio between the intensity of the 7-radiation from radium C and the actual amount of this product, and also between the amount of this product and that of radium, the measure of the 7-radiation is a measure of the quantity of radium in the prepa ration under examination.
Radium 3 1 2 X 4
Radioactive Properties.—The chief particle emitted by radium on disintegration is an a-particle with a range in air of 3.39 cm. at 15° C and the ordinary pressure. (The range is a distance characteristic of a radio-element traversed by its a-par ticle, beyond which the latter cannot be identified by any known instrument.) The velocities with which the particles issue from the source of radium are identical and equal to 1,510 millions of centimetres (9,38o miles) per second. The number of a-particles emitted per sec. by 1 gm. of pure radium is about 37,00o millions, a number obtained experimentally by counting the flashes per second made by the impact of the particles on a luminescent screen of zinc sulphide, placed at a known distance from a minute fraction of radium of known mass. An idea of the colossal num ber of atoms which compose 1 gm. of radium (and similarly, of course, for any other substance) may be gained from the state ment that despite the destruction of 37,00o millions of atoms of radium per sec. through disintegration, the actual loss of radium is only about 0.04% in a year. Iexplorer 4 1 5.
Radium 3 1 2 0
Radium 3 1 2 Bath House
No less remarkable is the amount of energy liberated by radium. This amounts to 25.5 calories per hour or 223,000 cal. per year for every gram of pure radium. This energy shows itself partly as heat (all radium preparations warm the objects in their near vicinity), and partly as light (glowing in the dark). Such an evo lution of energy without apparent diminution (the diminution is only 1 in 2,280 parts in a year) is on much larger scale than that obtained from chemical reactions. It is much higher indeed than has been indicated because the figures given refer to radium free from its products. With its products radon, radium A, radium C', and polonium, which themselves expel particles (see table), the energy evolution per year is as high as 1,236,00o calories. This,
owing to the slow rate of decay of radium, will not be reduced to half, it may be calculated, until after 1,58o years, or to a quarter until after 3,16o years, or to an eighth until 4,740 years have gone by. Backgrounds 7 4th. The evolution will, in fact, go on for ever, although at a steadily diminishing rate. Such a rate of energy emission is about a million times greater than that from an equal weight of chemical reactants.
Radium, in addition to its a-particle, expels also a compara tively unimportant 0-particle and a feebly penetrating 7-ray. These must not be confused, however, with the 0-particles and the 7-radiation which are emitted by preparations of radium. If a preparation containing radium be sealed up so that its gaseous product radon may not escape, then quickly there form in it radon, radium A, B, C and C' (which in a month have formed in maximum amount), and more slowly there form radium D, radium E and polonium (which in about 150 years reach their maximum amount). Since these products expel a- and 0-particles, and in one case a penetrating 7-radiation, the radiations from radium appear much more complex than those from radium with out these products. Radon, radium A, radium C' and polonium expel a-particles with ranges in air of 4.52, 4.72, 6.97 and 3.925 cm., respectively (cf. radium, 3.39 cm.) ; radium B and radium C expel very penetrating, and radium D and radium E feebly pene trating, 0-particles; accompanying the /3-particle from radium-C is a very penetrating 7 -radiation.
Physiological Effects.—A strong source of radium, if left on the skin for some time, causes sores which have the appearance of burns; prolonged exposure to the radiations leads to atrophy of the part affected and perhaps to cancer. Under suitable condi tions, however, the rays from radium have been successfully used in the treatment of cancer and are undoubtedly beneficial in this and similar conditions, though it cannot yet be said that radium is a 'cure' for all forms of this scourge. Even when it cannot be averred that the rays heal, it is established that they relieve pain in cancerous conditions. Healthy tissue is from four to seven times more resistant to the action of the rays than diseased tissues, and in conditions in which the diseased tissue may be destroyed without any of the healthy tissue radium is very beneficial. Young plants benefit in growth when exposed to a certain small amount of radiation (it is administered principally as radon) but are harmed by a larger amount. In this respect the rays resemble other specifics which are beneficial in small, but harmful and even poisonous in large, amounts when applied to living things. A strong source of radium can destroy the vitality of seeds and kill the bacteria which cause typhus, cholera, anthrax and similar diseases; even caterpillars have been killed by the rays. In 1906 it was claimed that the rays from radium could cause spontaneous generation, a claim that was never confirmed and is now regarded as fantastic.