2_kurs_4_semestr

4. Put the verbs in brackets into the correct tense to make correct type 3

conditional sentences.

1. If you …hadn’t been… (not/be) in a hurry, you …wouldn’t/might not have

forgotten… (not/forget) your keys.

2.If he … (remember) earlier, he … (send) her a birthday card.

3.If you … (not/be) ill, you … (go) to the party.

4.Jason … (not/break) his arm if he … (be) more careful.

5.Helen … (get) wet if she … (not/take) her umbrella.

6.If I … (do) my homework, my teacher … (not/shout) at me.

7.You … (pass) the test if you … (study) more.

8.If she … (close) the gate, the rabbit … (not/run) away.

9.She … (lose) her keys if I … (not/pick) them up.

10.If he … (save) some money, he … (be able) to go on holiday.

5. Read the story below and write type 3 conditional sentences, as in the

example.

Ben offered to help his neighbour fix the roof so he climbed up the ladder. He fell off the ladder and broke his leg. He went to hospital. He met Linda there. They fell in love and got married six months later.

1. If Ben hadn’t offered to help his neighbour fix the roof, he wouldn’t have climbed up the ladder. 2. If he hadn’t climbed up the ladder, …

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UNIT 6

Types of Radioactive Decays

Read the text and be ready to answer the teacher‟s questions.

There are three main types of radiation:

Alpha radiation;

Beta radiation;

Gamma radiation.

The reason alpha decay occurs is because the nucleus has too many protons which cause excessive repulsion. In an attempt to reduce the repulsion, a Helium nucleus is emitted. The way it works is that the Helium nuclei are in constant collision with the walls of the nucleus and because of its energy and mass, there exists a nonzero probability of transmission. That is, an alpha particle (Helium nucleus) will tunnel out of the nucleus. Here is an example of alpha emission with plutonium:

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The alpha radiation is the most dangerous of the three types of radiation, but a sheet of paper is enough to protect oneself. The skin protects us also from alpha radiation.

In nuclear physics, beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. There are three main types of beta decay: beta minus decay, beta plus decay and electron capture.

When we talk about the beta minus decay a neutron decays into a proton, an electron and an antineutrino. The electron and the antineutrino are emitted. The radioactive particle is the electron. The number of nucleons does not change, but we have got one proton more than before the decay. Two or three centimeters of wood are enough to protect oneself.

When we talk about the beta plus decay a proton decays into a neutron, a positron (the antiparticle of the electron) and a neutrino. The positron and the neutrino are emitted. The radioactive particle is the positron.

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When we talk about the gamma decay high-energy electromagnetic waves are emitted from the atomic nucleus. These waves are photons, which have got a higher frequency and fewer waves long than light. A gamma decay can happen after alpha decay or beta decay, because the atomic nucleus is very energetic. You need a big wall of lead to protect yourself from gamma radiation. Here‘s a diagram of gamma decay with helium-3:

Answer the following questions.

1.What type of particle is released in alpha decay?

2.What are the three main types of beta decay?

3.What is emitted due to gamma decay?

1.Some substances give out atomic or … radiation all the time, whatever is done to them, and these are said to be … .

2.There are … types of radiation emitted by radioactive … :

3.… radiation is easily absorbed by a few centimeters of … or a thin sheet of

… .

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4.… radiation easily passes through air or paper but is mostly absorbed by a few millimeters of … .

5.… radiation is very … and requires many centimeters of … or several meters of … to absorb most of it.

6.There are radioactive substances all around us, including e.g. granite … in the ground, in the air, in building materials and in food.

7.Radiation also reaches us from outer … . The radiation from all these sources is called … radiation.

8. is the … warning symbol for … .

The three types of radioactive emissions are called alpha (α), beta (β) and gamma (γ) radiation. Complete the table below with the correct information about each type.

Alpha

Beta

Gamma

Which of the three radioactive emissions (α, β, γ) best fit the following statements?

1.These emissions are charged. ___

2.This emission is the most massive (heaviest). ___

3.This emission is the most charged. ___

4.This emission is the most dangerous outside of the body. ___

5.This emission is stopped by thin paper or a few centimeters of air. ___

6.This emission can travel through paper, but is stopped by aluminium. ___

7.This emission can travel through fairly thick lead. ___

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GRAMMAR

Conditionals. Revision.

EXERCISES

1. Put the verbs in brackets into the correct tense.

1.A: Mum, Dad shouted at me.

B:Well, if you …hadn’t been… (not/be) naughty, he …wouldn’t have

shouted… (not/shout) at you.

2.A: I don‘t know what to do about my problem.

B:If I … (be) you, I … (talk) to my boss.

3.A: If I … (win) lots of money, I … (buy) a new house.

B:That‘s a nice idea. I … (buy) a new car.

4.A: I failed my exam today.

B:Well, if you … (study) harder, you … (not/fail).

5.A: I‘ve got terrible toothache.

B:If I … (be) you, I … (go) to the dentist‘s.

6.A: I‘m sorry.

B:What for?

A:If I … (not/leave) the door open, the puppy … (not/escape).

7.A: Why are you upset?

B:Because it‘s all my fault. If I … (not/be) late, we … (not/miss) the bus.

8.A: Where … (you/go) if you … (can) travel anywhere in the world?

B:If I … (can), I … (go) to America.

9.A: I‘ve lost my bag with my purse and my keys inside.

B:Well, if I … (be) you, I … (report) it to the police.

10.A: Ouch! I dropped a glass and cut my finger.

B: Well, if you … (be) careful, you … (not/cut) yourself.

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2. Complete the sentences.

Model: He wouldn‘t fail the exam if he …

He wouldn’t fail the exam if he paid more attention to his lessons.

1.If you see Alec …

2.If he had had more practical experience, the work …

3.They would have prepared for the examination better if …

4.We should play the game outdoors if …

5.We want to meet tomorrow evening if …

6.I should be very glad if …

7.If you had gone to the stadium, …

8.We should have organized the competition better if …

9.The patient would have been better if …

10.If we leave right now, we …

3.Henry is lost in the forest and he‟s thinking. Use his thoughts to write conditional sentences, as in the example. Then, state the type of conditional (1, 2 or 3).

1.If I hadn’t left the map at home, I wouldn’t have lost my way. (3)

2.…

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UNIT 7

Home-reading

Marie and Pierre Curie

Born in Poland during a time of Russian domination, Marie Sklodowska (1867-1934) had no real opportunity for an education after high school. She saved her hard-earned money to help pay for her older

sister‘s medical studies in Paris, then followed her to France in 1891, studying at the Sorbonne. In 1894, she met the French chemist Pierre Curie (1859-1906), and they were married a year later. Although Pierre had already made a name for himself, their collaboration proved far more fruitful than his solo career.

They spent much of their careers studying radioactivity (a term coined by Marie), examining the particles and energy produced as radioactive atoms decayed, and in the process learned about the building blocks of matter. They established that the heavy element thorium was radioactive and discovered two new elements: polonium and radium. They refined techniques for extracting radium from ores.

Marie won Nobel Prizes in both physics and chemistry for their work. (Pierre failed to share in the second simply because he was dead.) Yet despite living in near poverty they spent most of their money on further research. They were idealistic enough to refuse to patent any of their potentially lucrative discoveries. Pierre was killed when he was run down by a horse-drawn carriage. Marie died of leukemia, almost certainly the result of a lifetime of exposure to high levels of radiation. Ironically, one of the enduring applications of their work has been in the treatment of cancer with radiation.

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