Discuss these questions with your partner.

Do you know of any famous people who had to struggle to succeed?

What did they achieve?

Do you think you could be so strong?

H D Vocabulary

Complete the sentences below with words from the box.

hardship	enroll
resign	appoint
confirmed	resulted
■ solution	expand
■ density	uniform

1. They are going to a new

professor in the Chemistry department.

2. Many famous people in the past suffered

a lot of to achieve their goals.

3. The experiment proved that the gases had

a reaction, that is the

same reaction.

4. Most schools expect you to

before you begin your studies.

5. The of a substance is how

thick and compact it is.

6. If metal is heated you will see it

1. It was a made up of water

and salt.

8. If somebody is unhappy in their job, they may

9. The experiment in the lab in a huge explosion.

10. The outcome of the experiment his theory.

H Reading 2

Dmitri Mendeleev

Dmitri Ivanovich Mendeleev was born in Tobolsk, in Siberia, on 7^th February, 1834. As a child he showed a great interest in Mathematics and Physics and was a talented student. Despite the hardships experienced by his family while he was growing up, his mother was determined to see him educated and to help him achieve his dreams. After the family moved to St Petersburg, she managed to enrol him as a student science teacher on a full scholarship. Despite many more problems, Mendeleev earned his degrees and eventually, in 1863, was appointed Professor of Chemistry at the Technological Institute and the University of St Petersburg.

Probably his greatest scientific achievement was the discovery of the periodic law and the development of the periodic table of elements.

He left gaps in his table for undiscovered elements and predicted the properties of the elements that would fit these gaps. His predictions were confirmed when, during his lifetime, three predicted elements; gallium, germanium and scandium, which he had named eka-aluminium, eka-silicon and eka-boron respectively, were discovered. These discoveries gave him great respect among members of the scientific community.

However, Mendeleev made other important contributions to science. He was involved in many areas including hydrodynamics, agricultural chemistry, mineral recovery, meteorology and chemical technology. One particular contribution involved solutions. He spent a lot of time studying how the nature of solutions could be determined, adding greatly to our understanding in that field.

In addition, he was involved in physical chemistry, looking at the expansion of liquids because of heat. He spent time in Paris with Henri Victor Regnault studying the densities of gases and came up with a formula to explain how gases are uniform when expanding; in other studies he defined the absolute boiling point of a substance. His studies of gases at high and low pressures moreover, allowed him to develop an accurate barometer and while working for the Russian navy, he came up with pyrocollodion, a smokeless powder based on nitrocellulose. The list of his achievements is endless!

Despite his international reputation as one of the world’s most important scientists, the Tsar at the time did not approve of Mendeleev’s politics, resulting in his resignation from the University of St Petersburg in 1900. He died on 20^th January, 1907, from pneumonia.

ОПЫГЪ СИСТЕМЫ ЭЛЕМЕНТОВ*.

ОСК0«ЛНИ0Й нл «П АТОККОМЪ ltd И ХКЯЩЕСКОЯЪСХСЯСТГк.

Ti-SO Zr=. 80 7-180.

V_51 Kb- 94 T*—182.

Cr-M Mo- 96 W-iee.

Mn — 55 Rh-104,4 Pt-197,1.

F«=.56 Rn—104,4 lr=* 198.

NI — C« =■ 59 PI-106,» 0- “ 189.

H = 1 Cu — 63,4 Ag—108 Hg — 200.

Be» 9,4 Mg •• 24 Zn«65,t Cd-112

8=11 AI-=27,» ?-69 Uf =■ 116 Au-197?

C=I2 Si-28 ?=70 Sn=ll8

N=14 P-31 As—?S Sb=»l22 81 = 210?

0 = 16 S-32 Se —79,4 Те* 128?

F = !9 CI-35,*Br=80 1-127

Li = 7 Na = 23 K = 39 Rb-=85,i Cs>=133 TI-504.

С» —40 Sr-87,» Вд —137 Pb=>207.

? —45 Ce-92 ?Er-56 U-94 ?Yi —60 Di —95 ?)n~75,»Th-tl8?

Д. МекдахЬгаг

Pronunciation guide

eka-boron /екэ'Ьэ:гэп/ germanium /c^i'meiniam/ nitrocellulose /naitrsu'seljulsus/ pneumonia /njumounia/ pyrocollodion (pairauks'budian/ Regnault /гепэ:/

И E Comprehension

Read the text and answer the questions in your own words.

1. What position did Mendeleev achieve at the University of St Petersburg?

2. Why did Mendeleev leave gaps in the periodic table of elements?

3. How were Mendeleev’s predictions proven correct?

4. What contribution did Mendeleev make in the area of solutions?

5. What did Mendeleev’s formula concerning gases explain?

Before you listen

Discuss these questions with your partner.

What do you know about atoms and electrons? What do you know about chemical reactions?

И F Listening H)))

Listen to a teacher explaining to a class how electrons work. Then complete each sentence with one word.

1. Mendeleev didn’t know about

2. The periodic table arranged by Mendeleev was based on atomic

3. Electrons are located in

around the nucleus of an atom.

4. Valence electrons determine the properties of an element.

5. Lithium and have only one

valence electron.

6. Lithium and boron have

electron shells.

D

H G Speaking

H H Writing

iscuss these questions with your partner.

Besides the nucleus and electrons, what else is found in an atom?

-» Do you think scientists will discover any more elements?

Task

Prepare a short presentation to answer the question:‘What is the periodic table?’ Use the information in both texts.

Talk about:

• who devised the periodic table

• what is contained in the periodic table

• the role of electrons

• how the modern periodic table works

First complete these notes. Use them in your presentation.

Periodic table: An arrangement of

The first periodic table proposed by

was based on

Electrons determine

The modern periodic table is arranged

Remember to:

• read the texts very carefully

• make sure you understand the scientific processes

• try to use your own examples and explain them clearly

Write a magazine article for your school magazine about the history of the periodicity of elements. Use these notes to help you.

PARAGRAPH 1 Introduction

Briefly explain what periodicity is, and where the concepts of electrons and atoms were first developed.

Vocabulary:

In ancient times ... , during the 18^th century ...

PARAGRAPH 2

Write about the work of Mendeleev; arrangement by atomic weight.

Vocabulary:

organised according to ... , grouped by ...

PARAGRAPH 3

The role of electrons; how electrons are the basis of the modern periodic table.

Vocabulary:

the function of ... , is based on ...

PARAGRAPH 4 Conclusion

If you think new elements will be discovered in the future; the expansion of the periodic table.

Vocabulary:

In the years to come, I would imagine ...

Write 200-250 words.

Speaking tips

• Use time markers such as ‘firstly’, ‘next’ and ‘then’.

• Don’t speak too quickly; take your time.

• Refer to your notes.

B efore you read