4.2. Correct the mistakes in tense usage:

1. After the discovery of x-rays, another form of penetrating rays discovered.

2. In 1896, French scientist Henri Becquerel was discovered natural radioactivity.

3. Many scientists of that period was working with cathode rays, and other scientists were gathered evidence on the theory that the atom can be subdivided.

4. Some of the new research showing that certain types of atoms disintegrate by themselves. Henri Becquerel discover this phenomenon while investigating the properties of fluorescent minerals

5. Ernest Rutherford, who does many experiments studying the properties of radioactive decay, name them alpha, beta, and gamma particles, and classify them by their ability to penetrate matter.

6. By 1929, industrial radiation sources had becoming available for radiographing extremely thick materials.

7. The Curies extract uranium from ore and found that the leftover ore show more activity than the pure uranium.

8. During World War II and the race to produce a nuclear weapon, much were discovered about radioactive materials, and manmade isotopes was became available.

9. Manmade sources developed to penetrate even thicker materials; however, they also caused more damage to persons exposed to the radiation.

10. Roentgen was discovered that very penetrating radiations produced from the anode, which he called x-rays.

4.3. Open the brackets using the necessary tense form

The Discovery of Radioactivity.

In 1896 Henri Becquerel (to use) naturally fluorescent minerals to study the properties of x-rays, which (to discover) in 1895 by Wilhelm Roentgen. He (to expose) potassium uranic sulfate to sunlight and then (to place) it on photographic plates wrapped in black paper, believing that the uranium (to absorb) the sun’s energy and then (to emit) it as x-rays. This hypothesis (to disprove) on the 26^th-27^th of February, when his experiment (to faille) because it (to be) overcast in Paris. For some reason, Becquerel (to decide) to develop his photographic plates anyway. To his surprise, the images (to be) strong and clear, proving that the uranium emitted radiation without an external source of energy such as the sun. Becquerel (to discover) radioactivity.

4.4. Study the following words with prepositions and translate them

to apply to, to be interested in, to be based on, to be converted by, to refer to, to break into, to be capable to, to treat with, to expose to, to divide into

4.4.1. Find English equivalents for the words in brackets in the table 4.4. Complete the sentences using necessary tense form (active or passive)

1. When a high voltage (было применено) к the electrodes, electrons formed at the cathode would be pulled towards the anode and strike the copper with very high energy.

2. Only a few scientists (были заинтересованы) в Becquerel's findings.

3. The quantity of radioactive material (основано на) its activity rather than its mass.

4. In this decay a neutron in the nitrogen nucleus (преобразуется путём) the weak interaction into a proton, an electron and an antineutrino

5. Radiation ( относится к) the particles or energy released during radioactive decay.

6. Spontaneous fission is also known as “splitting the atom” as the nucleus (распадается на) two parts.

7. Ionizing radiation is high energy radiation that (способна на) alter atoms.

8. Some people (лечат) radiation to cure disease.

9. Everyone (подвергается) radiation on a daily basis.

10. Medical uses of radiation (делятся roughly на) therapy and diagnosis.