Notes on the text

1. ushered in a new era – оповістило нову еру

2. to call for – вимагати

3. half-life – період напіврозпаду

4. to dispense with – обходитися без

Vocabulary

oсcur – траплятися

essence - есенція

nuclide – нуклід

accuracy – точність

comprise – містити

expose – підлягати

whereas – тоді як

excite – хвилювати

explanation - пояснення

vital – життєвий

disease – хвороба

Exercises

1. Answer the questions

1. Who discovered phenomenon of radioactivity?

2. What is the phenomenon of radioactivity is based on?

3. What are the milestones in the history of radioactivity?

4. Where can radioactivity be applied?

5. What is the most interesting field of applications of radioactivity?

6. Where are radioactive nuclides applied now?

2.Find the pairs of antonyms:

long-lived, artificial, dependent, slow, natural, independent, outside, discovered, inside, undiscovered, short-lived, rapid.

3. Translate the following words with the same root:

1)to consider, consideration, considerable, considerably; 2) to produce, production, productivity, product; 3) to depend, dependence, dependent, independent; 4) to use, use, useful, useless, usefulness; 5) to discover, discovery, discovered; 6) to add, addition, additional.

4.Open the brackets choosing the correct form of the Participles:

1. A positively (charging, charged) particle having the mass of the electron was discovered in 1932. 2. The scientist found that X-rays (produced, producing) were complex. 3. According to this theory (dealt with, dealing with) atomic structure the nucleus is a very small, compact, central part of an atom. 4. Oppositively (charged, charging) particles exert forces of attraction on one another. 5. Elements (composed, composing) of atoms containing only one or two valence electrons usually form positive ions. 6. (Investigated, investigating, having investigated) this phenomenon the scientists can make some important conclusions. 7. The work (doing, done) by these researchers resulted in many new discoveries. 8. The ions (involving, involved) can be used as a highly sensitive detector of radiation. 9. The investigation (followed, following) by many experiments was of great importance. 10. The nuclei (formed, forming) in this reaction are unstable.

4. Read and translate the text The discovery of X-Rays and Radioactivity

Several great scientific discoveries were made in a period of a few years, beginning in 1895. These discoveries made great changes in chemistry as well in physics. X-rays were discovered in 1895, radioactivity in 1896, the new radioactive elements polonium and radium were isolated in the same year, and the electron was discovered in 1897.

W. Rontgen reported that he had discovered a new kind of rays called X-rays. These rays are produced when electricity is passed through a tube. The rays are outside of the tube, they radiate from the place where the cathode-ray electrons strike the glass.

Soon after the discovery of X-rays the French physicist Henry Becquerel investigated some minerals containing uranium. He found that these minerals emit rays that like X-rays can pass through black paper and expose a photographic plate. He also found that the radiation produced by the uranium minerals could, like X-rays, discharge electroscope.

Mary Curie began a systematic investigation of “Becquerel radiation” using the electroscope as a test. She found that natural pitchblende, an ore of uranium, is several times more active than purified uranium dioxide.