Structure of the atom

The atom is the basic particle of all matter. All solids, gases, and liquids are composed of atoms.

For a time the atom was considered to be indivisible but then it has been found that the atom in its turn can be divided into many different, components.

In dividing the atom, man releases forces of great magnitude. These are forces that bind the central core of the atom. This central core – the nucleus – is extremely small in diameter.

The nucleus of the atom is of a highly complex structure. It is the three main components of the atom that we shall deal with below. These are called protons, neutrons and electrons.

The proton carries a positive charge of electricity, the number of protons in the nucleus determining the element that the atom forms.

For example, if the nucleus has a single proton, then it will form the gas hydrogen. If 92 protons are present, the element will be uranium and so on. In short, if the number of protons in the nucleus is known, the element can be found out at once.

As mentioned above, the proton carries a charge of positive electricity. We know the bodies charged with the same kind of electricity to repel one another. When two protons are brought close together they repel one another with great force.

The second of these basic components of the nucleus is the neutron. The neutron does not carry a definite electric charge. The sub-particles that form the neutron do carry charges but the charge of one balances that of another, leaving the neutron neutral. It is from this state that it gets its name.

The third component of the atom is the electron. The electrons revolve around the nucleus. Each electron carries a negative charge of electricity that is equal to the positive charge of a proton in the nucleus.

Вариант № 3

1. Перепишите следующие предложения. Определите по грамматическим признакам, какой частью речи являются слова, оформленные окончанием -sи какую функцию это окончание выполняет, т.е. служит ли оно:

1. показателем 3-го лица единственного числа глагола в PresentIndefinite;

2. признаком множественного числа имени существительного;

3. показателем притяжательного падежа имени существительного (см. образец выполнения 1).

Переведите предложения на русский язык.

1. Usually a lab assistant shows the equipment to the students.

2. Students choose the major subject and take many courses in this subject.

3. After four years they get a traditional Bachelor’s Degree.

2. Перепишите следующие предложения, содержащие разные формы сравнения, и переведите их на русский язык.

1. The more you work the better you know English.

2. My friend is one of the best students of our group.

3. What is the most popular sport in your country?

3.Перепишите и письменно переведите предложения на русский язык, обращая внимание на перевод неопределённых и отрицательных местоимений.

1. Can anybody show me the way to the station?

2. The commission found nothing wrong.

3. Something important took place there.

4. Перепишите следующие предложения, определите в них видо-временные формы; переведите предложения на русский язык .

1. I have attended lectures on history since May.

2. He was looking through a newspaper when I rang up.

3. This young woman teaches mathematics at our University.

5. Перепишите следующие предложения и переведите их на русский язык, обращая внимание на разные значения слов it,that,one.

1. One can see that there is no principal difference between iron and copper as conductors.

2. It is the number of electrons within the atom that determines the properties of a substance.

3. It is necessary to use the latest means of control in industry.

6. Перепишите следующие предложения; подчеркните в каждом из них модальный глагол и его эквивалент. Переведите предложения на русский язык.

1. Man-made satellites had to use solar cells as a source of power.

2. The application of digital computers should include all forms of automatic control in science and industry.

3. The students cannot translate this text because it is difficult

7. Прочитайте и переведите текст.

Higher Education in the USA

There is no national system of higher education in the United States. Higher education is given in colleges and universities. There are over 2100 various higher educational institutions, including colleges, technological institutes and universities. The average college course of study is 4 years. The academic year is usually 9 months or 2 terms (semesters) of four and a half months each. Classes usually begin in September and end in June. The first-year students are called freshmen.

Students choose a major subject and take many courses in this subject. After four years, they get a traditional Bachelor's degree. Then the students may go on to graduate school and with a year or two of further study get a Master's degree.

After another year or two of study and research, they may get a still higher degree as Doctor of Philosophy (Ph. D.). The student's progress is evaluated by means of tests, term works and final examinations in each course. The student's work is given a mark, usually, on a five point scale. Letters indicate the level of achievement. "A" is the highest mark. "F" denotes a failure.

Most American colleges and universities charge for tuition. The methods of instruction in the universities are lectures, discussions, laboratory and course works or seminars.

Most cities have colleges or universities that hold classes at night as well as in daytime. In this way people may work for a degree or just take a course in the subject that interests them.

8. Прочитайте и переведите текст.