1. Consult the text above and complete the following sentences.
1. Atomism reentered scientific ... in the 19th century.
2. Dalton … a chemical atomic theory.
3. Dalton experimented with elements to obtain relative … weight.
4. Robert Cecil … a number of questions about the atom.
5. The … tube clarified some questions.
6. William Crookes discovered that the space inside the tube … .
7. Under the influence of a magnet rays can … .
8. Stoney introduced the term … .
9. While experimenting with covering tubes with screens Roentgen made an amazing … .
2. Some of the words given in bold type in the text have synonyms and antonyms mentioned there. Find and name them.
3. Some dates (namely, years) are mentioned in the text: 1803, 1855, 1874, 1894, 1895. Can you recollect the events that took place at that time? If necessary, consult the text.
4. Match the names of famous people with the proper information about them. Add some more facts about these people.
| John Dalton | suggested to call the unit of charge “electrine”. |
| Wilhelm Roentgen | developed a mercury pump |
| James Stoney | discovered that the airless space inside the tube glowed. |
| Robert Cecil | discovered a new type of ray. |
| William Crookes | created a table of elements. |
| Heinrich Geissler | posed questions about the atom |
5. Below you will find some theses of Dalton’s atomic theory. Which of them are right and which of them are wrong? Correct the wrong facts (or information).
- Atoms combine to form chemical elements.
- Atoms of any one element are identical in their masses.
- Atoms of different elements have different masses.
- Atoms can only combine in small, whole-numbered rations.
- Atoms are unchangeable and indestructible.
6. Robert Cecil posed a number of questions while speaking to the British Association for the Advancement of Science.
1. Name these questions.
2. Are all these questions solved? If yes, then when and by whom.
7. Comment on the role the cathode-ray tube played in getting information about rays and their properties. (Mention experiments made by Crookes, Stoney, Roentgen).
8. Arrange the following sentences in the logical order to sum up the information given in the text.
1. The cathode-ray tube was used to cast light on some problems.
2. While speaking to the British Association Robert Cecil posed some questions about the atom.
3. Dalton put forward a chemical atomic theory and created his table of elements.
4. William Crookes found out that the glow would become a ray when the end of the tube was closed off with glass and the cathode and the anode were placed inside the tube.
5. He discovered a new type of ray.
6. At the beginning of the 19th century atomic theory was revived.
7. Roentgen managed to determine the nature of the fluorescent light.
8. Rays consist of particles having charge.
9. In pairs, discuss the information given in the text.
10. You are to prepare a report about the atomic theory of the 19th century. Use the text given above and add some facts to speak on the point.