The discovery of radioactivity

The existence of penetrating radiation that could pass through layers of opaque materials as if they were made of clear glass was а recognized fact at the time of Becquerel's discovery. In fact, only а year earlier (1895) а German physicist Wilhelm Roentgen (1845-1923), discovered X-rays, which can penetrate equally well through cardboard, black paper, or the human body. But there was an important difference between the rays discovered by Becquerel and the X-rays. While special equipment was required to produce X-rays, the radiation discovered by Becquerel was flowing from the piece of uranium ore without any external excitation. It was Marie Curie who invented the term ‘radioactive’ to describe a substance that gave out these new rays all the time. The early studies of the newly discovered phenomenon which was called radioactivity, showed that the emission of mysterious radiation was completely unaffected by physical or chemical conditions.

It was soon found that this property of emitting penetrating radiations was not confined to uranium and its compounds. Thorium and its compounds and minerals containing thorium have this same property. Such substances are said to be radioactive. Ву studying the radioactive mineral called pitchblende (урановая смолка) which contained uranium and thorium Pierre and Marie Curie found that this mineral contained substances which were much more radioactive than either uranium or thorium. The Curies finally isolated two new elements. Marie called the first one ‘polonium’ after Poland, where she was born. The second one was called ‘radium’ because it was highly radioactive.

Exercise 1. Use Reading 3-C to find the English equivalents for the following Russian phrases.

Существование проникающего излучения; признавать - признанный факт; требовать специального оборудования; без внешнего возбуждения; ограничиваться соединениями урана; не зависеть от физических и химических условий; обладать таким же свойством; выделить новый элемент; как уран, так и торий; либо уран, либо торий; ни уран, ни торий.

Exercise 2. Summary writing. Answer the questions below and write down your answers. You will get thirteen simple sentences.

1. Was penetrating radiation quite a new phenomenon at the time of Becquerel or was it a recognized fact?

2. Were X-rays discovered by Roentgen a year earlier?

3. Can X-rays discovered by Roentgen penetrate through opaque substances easily?

4. Is there a difference between X-rays and the rays discovered by Becquerel?

5. Do X-rays require special equipment?

6. Do Becquerel’s rays flow spontaneously from a piece of uranium ore?

7. Was the emission of mysterious radiation completely unaffected by physical or chemical conditions?

8. Is the spontaneous radiation confined to uranium compounds?

9. Do thorium compounds have the same property?

10. Did the Curies study pitchblende?

11. Is pitchblende a mixture of uranium and thorium?

12. Did they isolate new highly radioactive substances?

13. Did they call them polonium and radium?

Combine the sentences to make five complex sentences and write them as a paragraph. You can join the simple sentences in the following way:

1. Join 1 and 2 by means of «in fact».

2. Join 3 and 4 by «however».

3. Join 5 and 6 by «while».

4. Join 6 and 7 by «therefore», «thus», «so».

5. Join 8 and 9 by «as».

6. Join 10 and 11 by «which».

7. Begin 12 with «As a result…»

8. Join 12 and 13 by «which».

Do you know?

Pitchblende is an old name for uraninite, which is uranium ore mineral, basically uranium oxide. Pitchblende is also the rock in which Marie Curie discovered radium.

Pitchblende was first discovered in the silver mines of St. Joachimsthal (now the Czech Republic), as a material that accompanied rich silver deposits. «Pitchblende» comes from the German word «pechblende». The German word «blende» means «mineral», while «pech» means «bad luck», so it was literally the «bad-luck-mineral». Seeing this mineral was never welcome: it usually meant that there was no more silver left in the mine and that miners would have to work hard to start a new one. Pitchblende was useless at the time it was named. That was because nobody had a use for uranium at the time.

The town of Joachimsthal is also known to have given its name to the U.S. dollar. In the 16th century, the silver mined there was used to produce coins, which were called «Joachimsthalers». The name was later shortened to «thalers» (талеры), and then changed into «dollars» in English-speaking countries.

Isn't it ironic that a small town in the Czech Republic gave us the two things that shaped the modern world? Both have changed, and continue to affect our lives, our politics and international relations.

Reading 3-D

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