1. Who was the phenomenon of natural radioactivity discovered by?
2. Was this discovery really made quite accidentally?
3. What problem did Becquerel study at the time?
4. What did he keep minerals for in one ofthe drawers of his desk?
5. What did he see when he developed the photographic plates?
6. Why did he begin checking all the boxes with the plates?
7. Under what conditions were the boxes kept?
8. What was the cause of this mishap?
9. Was Becquerel greatly surprized to discover the radiation?
10. What penetrating radiation was discovered a year before that?
11. Who discovered this radiation?
12. Who were the first investigators ofthe phenomenon of radioactivity discovered by Becquerel?
13. What conclusion did the first investigators come to? Why did they come to such a conclusion?
14. What substances is the radiation emitted from?
Be prepared to say a few words about.
1. The history ofthe discovery of natural radioactivity.
2. Radioactive elements and types of radioactive emissions.
3. Radioactive processes in nature.
4. Radioactive emissions and their applications (radioisotopes, radiobiology, radiocarbon dating, radiodiagnosis).
Match each word in Column I with its synonym in Column II.
to be the case, because of, since, to take into account, no matter, to affect, to cause, to be in vogue, to rule out
II
to exclude, regardless of, to influence, because, to happen, to be in fashion, on account of, to take into consideration, to bring about
• Fill in the blanks with the proper word using the words in brackets.
(purified, purely, purification)
1. The process of... is rather complicated.
It is a ... theoretical problem.
How is the material... in this case?
The discovery ofthe phenomenon of radioactivity was... accidental. (excited, excitation)
2. The radiation discovered by Becquerel was flowing without any external
... from the piece of uranium ore.
The highly ... atoms arc often called Rydbergatoms, aftcrthe Swedish spectroscopist Yohanncs Rydberg.
Both the ion and target atom undergo electronic... during the collision. (exposed, exposure)
3. The technique is based on the use of long... to record an object's motion.
The plates were badly fogged, as if previously ... to light.
Several ofthe animals which were ... to radiation have died since.
CLASSWORK
READING (9B)
• Skim the passage rapidly (2 min.) and answer the following questions.