Химия Answer the questions. просмотров - 246
One of the cornerstones of modern chemical theory is the Periodic Law. It can be simply stated as follows: The properties of the elements are a periodic function of the nuclear charges of their atoms.
In 1869 Mendeleyev arrived at the conclusion that by the arrangement of the elements in order of increasing atomic weight the similarity and periodicity of properties of various, valence groups of the elements were clearly delineated.
There were several vacant spaces in Mendeleev’s table which led him to predict the existence of six undiscovered elements, (scandium, gallium, germanium, polonium etc). His confidence in the new classification was clearly expressed in the predictions which he made of the chemical properties of these missing elements. And within fifteen years gallium, scandium and germanium were discovered.
Although this table has been modified hundreds of times, it has withstood the onslaught of all new facts. Isotopes, rare gases, atomic numbers, and electron configurations have only strengthened the idea of the periodicity of the properties of the elements.
|Periodic Law –періодичний закон cornerstone –наріжний камінь to state –формулювати as follows –наступним чином nuclear charge –ядерний заряд to arrive at a conclusion –прийти до висновку arrangement –розташування in order of increasing atomic weight –в порядку зростання атомної ваги similarity - схожість valence group –валентна група to delineate -окреслювати vacant space –вільне місце to predict -передбачати||existence -існування confidence -впевненість to express –виражати prediction -пророкування missing -відсутній within –протягом to modify -видозмінювати to withstand –витримувати onslaught –поява isotope –ізотоп rare gases –рідкі гази electron configuration –електронна конфігурація to strengthen -зміцнювати|
1. How many chemical elements are there now?
2. What is the symbol of Manganese?
3. What is a symbol usually derived from?
4. What does a subscript show?
5. What element is always designated first in the formula?
6.When did Mendeleyev discover the periodic law?
7. How can the Periodic Law be simply stated?
8. What elements were discovered after Mendeleyev modified the table?
9. Give some examples of polyatomic molecules of single elements.
10. What are simple diatomic molecules of a single element designated by?
2. True or false?
1) Symbols and formulas are used to indicate chemical reactions.
2) Groups of symbols are called equations.
3) Groups of symbols are called formulas.
4) There are 102 chemical elements now.
5) The more electropositive element is always designated last in the formula.
6) Subscriptions are used to designate the number of atoms of each element present in the molecule.
7) Mendeleyev made his discovery in 1879.
8) There were several vacant spaces in Mendeleev’s table which led him to predict the existence of six undiscovered elements.
9) The table wasn’t modified.
10)Properties of the elements are periodic functions of the nuclear charges of their atoms.
Dates Ordinal numbers Cardinal numbers Exercise 5. Write down the following in figures.1. twenty-five million seven hundred thirty-two thousand 2. ten million five hundred sixty-seven thousand five hundred fifty-two 3. two million one hundred fifty thousand one hundred thirty-one 4. one million six hundred eighty-two thousand twelve 5. one point three million 6. sixty-seven thousand and five 7. two hundred thousand ninety-five 8. forty-five... [читать подробенее]
1. Exercise 2. Have a look at the adverbs in bolt. Find them in the UNIT and guess their meaning. Read the quotations and translate them. Exercise 1. Find the Russian equivalent. 1. to indulge in 2. to prefer 3. to introduce 4. to expect 5. to proffer 6. to squeeze 7. to exchange 8. to gain A. расценивать B. выражать C. предлагать D. приобретать E. кричать F. следовать G. избегать H.... [читать подробенее]
Ex. 59. Complete the following sentences about the important moments in history using the Past Continuous form of the verbs in brackets. Ex. 58Read the story and rewrite it in the past tense. Ex.57 Using the Past Continuous tense, fill in the blanks with the correct forms of the verbs shown in brackets. Ex.56 Using the Past Continuous tense, fill in the blanks with the correct forms of the verbs shown in brackets. Then rewrite the following affirmative statements as questions... [читать подробенее]
Ex. 48. Explain the use of the Simple Past in the following sentences. The First TV Soap Opera Ex. 47. Put the verbs in brackets into the Past Simple. The first TV soap opera (a) ……….. (appear) on American television just after the Second World War. Its name (b) ………. (be) Faraway Hill and it (c) ……….. (begin) on the 2nd of October, 1946. A famous Broadway actress, Flora Campbell, (d) ………… (play) Karen St. John, a rich New York woman who (e) ……….... [читать подробенее]
EQUITY In a general sense equity means fairness. In English law, equity means that body of rules originally enforced only by the Court of Chancery. Equity has been described as “a gloss (meaning a supplement) on the common law”, filling in the gaps and making the English legal system more complete. Petitions from persons unable to obtain justice in the common law courts were sent to the King as “fountain of justice”. These petitions were sometimes examined by the King and Council... [читать подробенее]
Task 12. Fill in the blanks. Task 11. Guess the meaning of the international words using in the text. Task 10. Make up the questions. SUBMISSION SEAT 1) something to sitting on, e.g. a chair 2) a place where something is, or is located or based 3) a parliamentary constituency 4) membership in legislative body1) act of accepting the power or authority of another 2) legal theory, opinion presented to a judge or jury 3) the act of presenting something, e.g. a... [читать подробенее]
Task 10. Make up sentences using the following expressions. Judicial branch, according to, the highest tribunal, Chief Justice, to be appointed by, to be approved by, to alter, successful experience, to pass laws, to be authorized, principal duty, to be at stake. 1. What responsibility does the judicial branch have? 2. What kind of court is the judicial power vested in according to the Constitution? 3. Could you describe the Supreme Court of the USA? 4. What do you know about the... [читать подробенее]
Part two Discuss the following before you listen. You will hear an interview with Tim Rice, who wrote the lyrics for Part one The writerJesus Christ Superstar. It was first performed in the 1970s, but hasn’t been performed many times since. Andrew Lloyd Webber composed the music. a) What are some of the main events in the life of Jesus Christ? Who were some of the main characters in his life? b) Why do you think Tim Rice and Andrew Lloyd... [читать подробенее]
Ex. 3. Read and translate the text. The Randolf sisters, Sadie and Esther, live just a block away from each other. Sadie constantly complains that the people in town are cold and unfriendly, while Esther finds them warm and pleasant. Although Sadie can’t see it, the difference is in the way they approach those people. Sadie and her husband have a lovely house. It’s filled with beautiful antique furniture and glassware that is so fragile it could easily be broken by a careless guest... [читать подробенее]
Discussion Ex. 1. Read and translate the text. Ex. 2.Work in pairs. Ex. 1. Answer the questions. Discussion 1. What are the three types of housing mentioned? 2. What is the ratio of houses to flats in Britain? 3. What has happened to home ownership in Britain? 4. What sort of people in the UK are most and least likely to own their houses? 5. Explain the following: sheltered housing, a mortgage, a slum area.1. What differences are there between housing in... [читать подробенее]