Page 5 - Curriculum Visions Dynamic Book

Nuclear reactions are often far more powerful (they release much more energy) than chemical reactions. This is why they have been used in bombs as well as in power stations. However, when properly handled, they are not any more dangerous than chemical reactions.
Radioactivity – energy given out by a radioactive substance –
is a result of changes to the nucleus of an atom. The atoms of the radioactive elements send out, or radiate, particles and waves of energy from their core (nucleus) without any form of chemical reaction.
Radioactivity is as old as the Universe, yet it was only discovered quite recently. Radium, the first radioactive element to be discovered, was only noticed in 1896 when French scientist Antoine Henri Becquerel accidentally left an unexposed photographic plate in a drawer next to
a piece of ore which contained radium. When he developed the plate he
found that it had been “fogged” by the radioactivity from
the radium. The word radioactivity was suggested in the early years of this century by Pierre and Marie Curie, who did much of the pioneering
work on radioactive elements. Radioactive elements are not stable
like other elements. Because they continuously give out radiation, they are also always changing. Although radium and uranium are probably
the best known of the radioactive elements, there are many others with very useful properties, as we shall see.
 Testing the construction of the fuel rod assembly before inserting the radioactive material.
5
5