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Text IV.
I. Read the text using the words from the list:
Vocabulary list:
1. assumption(n) – допущение, предположение
2. lustre(n) – блеск
3. exposure(n) – выделение
4. dull(n) – тускнеть, матировать
5. tinge(n) – оттенок
6. lead(n) – свинец
7. potassium(n) – калий
8. sulphur(n) – сера
THALLIUM
Thallium made its public debut in 1862 at the International
Exhibition in London. The year before
W. Crookes searching by
spectrography for tellurium in the residues of a German sulfuric
acid plant noted an unaccountable green line in the spectrum. He
concluded that this line represented a new element.
With a poetic touch he compared the colour of the spectrum
line to the bright green tint of new vegetation and named the
element thallium from the Latin thallus—" a budding twig." He
was successful in obtaining a small quantity in metallic form for
display at the 1862 International Exhibition in London.
Controversies have often arisen as to the priority of a discovery,
and thallium was no exception. Professor A. Lamy, working
independently of W. Crookes, observed the same spectrum line in
the residues from another sulfuric acid plant and claimed credit
for its discovery. W. Crookes was, probably, prior to A- Lamy in
discovery and preparation by only a few months.
W. Crookes' assumption that thallium belonged to the sulphur
family was soon disproved as the physical and chemical
properties were investigated. Studies revealed that the element
was closely associated with lead, mercury, potassium and
aluminium. Mendeleev when publishing his atomic table placed
it in Group III under indium between mercury and lead; and this
has been its accepted place-ever since.
Thallium is found in potash minerals., which have no
commercial significance at present. Today the metal is recov-
ered mainly as a by-product from the roasting of pyrite ores in
the production of sulfuric acid and from the smelting of lead and
zinc.
Metallic thallium when freshly cut has a metallic lustre, which
upon exposure to air dulls to a bluish grey tinge resembling lead
in appearance. As a matter of fact, the properties of thallium are
very similar to those of lead.
Investigations of the systems of thallium and other elements
show that thallium readily alloys with many other elements, the
exceptions are copper, zinc, aluminium, nickel, and selenium.
2. Scan the text for information that answers the questions
below:
1. What was the year of thallium discovery?
2. Who named the element “thallium” and why?
3. What group of chemical elements is thallium associated with?
4. Where is thallium placed in the Mendeleev’s table?
5. What colour has this element when it is exposed to air?
3. Match the following words and definitions:
a. priority 1. a person or a thing is not included
b. mineral 2. a natural substance got from the earth
c. spectrum 3. to get knowledge of
d. resemble 4. an image of a band of colours
e. exception 5. to be similar to
f. property 6. high place among competing claims
Text IV. was closely associated with lead, mercury, potassium and
aluminium. Mendeleev when publishing his atomic table placed
I. Read the text using the words from the list: it in Group III under indium between mercury and lead; and this
has been its accepted place-ever since.
Vocabulary list: Thallium is found in potash minerals., which have no
1. assumption(n) – допущение, предположение commercial significance at present. Today the metal is recov-
2. lustre(n) – блеск ered mainly as a by-product from the roasting of pyrite ores in
3. exposure(n) – выделение the production of sulfuric acid and from the smelting of lead and
4. dull(n) – тускнеть, матировать zinc.
5. tinge(n) – оттенок Metallic thallium when freshly cut has a metallic lustre, which
6. lead(n) – свинец upon exposure to air dulls to a bluish grey tinge resembling lead
7. potassium(n) – калий in appearance. As a matter of fact, the properties of thallium are
8. sulphur(n) – сера very similar to those of lead.
Investigations of the systems of thallium and other elements
THALLIUM show that thallium readily alloys with many other elements, the
exceptions are copper, zinc, aluminium, nickel, and selenium.
Thallium made its public debut in 1862 at the International
Exhibition in London. The year before W. Crookes searching by
spectrography for tellurium in the residues of a German sulfuric 2. Scan the text for information that answers the questions
acid plant noted an unaccountable green line in the spectrum. He below:
concluded that this line represented a new element.
With a poetic touch he compared the colour of the spectrum 1. What was the year of thallium discovery?
line to the bright green tint of new vegetation and named the 2. Who named the element “thallium” and why?
element thallium from the Latin thallus—" a budding twig." He 3. What group of chemical elements is thallium associated with?
was successful in obtaining a small quantity in metallic form for 4. Where is thallium placed in the Mendeleev’s table?
display at the 1862 International Exhibition in London. 5. What colour has this element when it is exposed to air?
Controversies have often arisen as to the priority of a discovery,
and thallium was no exception. Professor A. Lamy, working 3. Match the following words and definitions:
independently of W. Crookes, observed the same spectrum line in
the residues from another sulfuric acid plant and claimed credit a. priority 1. a person or a thing is not included
for its discovery. W. Crookes was, probably, prior to A- Lamy in b. mineral 2. a natural substance got from the earth
discovery and preparation by only a few months. c. spectrum 3. to get knowledge of
W. Crookes' assumption that thallium belonged to the sulphur d. resemble 4. an image of a band of colours
family was soon disproved as the physical and chemical e. exception 5. to be similar to
properties were investigated. Studies revealed that the element f. property 6. high place among competing claims
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