Boys' Second Book of Inventions

Boys' Second Book of Inventions

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"[...]and Professor Curie has actually made a very small quantity of it, but it is unstable, immediately oxidised by the air and destroyed. So it is manufactured only in the form of chloride and bromide of radium. The "strength" of radium is measured in radio-activity, in the power of emitting rays. So we hear of radium of an intensity of 45 or 7,000 or 300,000. This method of measurement is thus explained. Taking the radio-activity of uranium as the unit, as one, then a certain specimen of radium is said to be 45 or 7,000 or 300,000 times as intense, to have so many times as much radio-activity. The radium of highest intensity in this country now is 300,000, but the Curies have succeeded in producing a specimen of 1,500,000 intensity. This is so powerful and dangerous that it must be kept wrapped in lead, which has the effect of stopping some of the rays. Rock-salt is another substance which hinders the passage of the rays.[...]."show more

Product details

  • Paperback | 106 pages
  • 152.4 x 228.6 x 5.08mm | 181.44g
  • Createspace
  • United States
  • English
  • black & white illustrations
  • 1507547455
  • 9781507547458