The History of Chemistry
There are five periods in the history o f chemistry. The ancient period comprising the older civilizations of China, India, Greece, and their contemporaries to 350 A. D. developed practical arts as in Egypt, and a philosophical approach to the study of matter as in Greece, where a theory of numbers, an atomic theory, and a theory of five elements, earth, air, fire, water and the quintessence were proposed.
The alchemical period (350-1500), of which the principal goals were an elixir of life and the philosopher’s stone by which base metals could be changed to gold, introduced pure substance and improved techniques.Iatrochemists (1500-1650) devoted their chemical pursuits to alleviation of disease. During the phlogiston period (1650-1774) men postulated a hypothetical matter whose presence was required for combustion and calcination. Gain in weight by calcination of metals led to a seareh for a very light material and subsequent discovery of gases, one of which was oxygen, and the answer to the problem. Ib is is the date when modem chemistry begins.
When qualitative and quantitative analysis had identified enough pure substances, inorganic chemistry grew in scope. Organic chemistry was little understood until 1828 when synthesis of urea by Fricdcrich Wohler (1800-1828), a German chemist, proved that the “vital force” which was considered imperative to producc compounds that occurred in living matter was not needed.
Meanwhile reliable physical and chemical measurement began with the laws of Boyle (1660), Charles (1785), Gay-Lussac (1808) and Dalton (1807). Dalton’s atomic theory (1807), postulated after the laws of the conservation o f mass and definite proportions were tacitly assumed, stimulated the 19th-century effort to determine accurate atomic weights,ideas for combination as expressed in valence*, and the studies of molecular structure until the thrcc-dimcntional models appeared.
Gradual determination of physical properties of the elements indicated a periodicity of property expressed by the periodic law which has withstood the onslaught** of the discovery of the subatomic particles which make up the nucleus and outer electrons of the atom.
Words and Word-Combinations to Be Memorized
accurate, A. D., ancient, approach, assume, comprise, date, definite, determine, effort, express, force, gain, goal, gold, gradual, improve, inorganic, matter, model, organic, outer, particle, principal, problem, prove, qualitative, reliable, require, stimulate, subsequent, synthesis, technique, there be, until, urea, withstand
Ex. 5. Give the Uzbek equivalents fo r th e following:
the history of chemistry, an ancicnt period, comprize, civilization, develop, a philosophical approach to, a theory of numbers, a theory of elements, propose, the alchemical period, the principal goal, base metals, change to, introduce, pure substance, an improved technique, devote, during the period, postulate, a hypothetical matter, require, gain in weight, the answer to the problem, identify a substance, synthesis of urea, produce a compound, reliable measurements, stimulate the effort, accurate weight, until, gradual, withstand smth., subatomic particles
Ex. 6. Give th e English equivalents fo r th e following:
qadimgi davr, kimyo tarixida materiyani o'rganish usuli, atom nazariyasi, elementlar nazariyasi, sonlar nazariyasi, er, suv, havo, ofony, asosiy maqsad, oltin, sof moddaga aylanish, talab, vazn ortish, juda engil modda, keyingi kashfiyot, zamonaviy kimyo, sifatli / miqdoriy tahlil qilish, moddani aniqlash, organik / noorganik kimyo, moddaning sintezi, isbotlash, aralashmani olish, ishonchli usul, massani saqlash qonuni, aniq vaznni aniqlash, keyingi urinishlar, yangi model, bosqichma-bosqich, aniq davriyligi ochilish zarralar yadro, tashqi elektronlar tashkil
Ex. 7. Fill in the blanks with prepositions where necessary .
1. There are five periods... the history... chemistry. 2. A philosophical approach... the study... matter was developed ... Greece. 3. Alchemists thought that there was a way ... which base metals could be changed ... gold. 4. ... the phlogiston period men postulated a hypothetical matter.5. Gain... weight... calcination... metals le d ... a seareh ... a very light
* as expressed in valence — выраженный валентностью
** has withstood the onslaught — выдержал атаку
material. 6. Organic chemistry was little understood ... the synthesis of urea... Wohler... 1828.7. Reliable physical and chemical measurements began... the laws... Boyle, Charles, Gay-Lussac and Dalton. 8. Subatomic particles make ... the nucleus ... the atom.
Ex. 8. Translate the sentences into Uzbek paying attention to diflcrcnt functions of the verb do.
1. Doit as quickly as you can. 2. Doyou know when the periodic law was stated? 3 .1 can’t doit now, 1 must be going. 4. The alchemists didimprove techniques during their seareh o f the philosopher’s stone and an elixir of life. 5. They do synthesize new materials in their laboratory.6. Scientists didnot understand organic chemistry before the synthesis o f urea. 7. He will have doneit by S o’clock.
Ex. 9. Translate the sentences into Uzbek.
a) 1. In the period 350-1500 A. D. alchemists devoted their efforts to a seareh for the philosopher’s stone. 2. Our understanding of atomic energy levels is based on modem advances in chemistry. 3. Reliable physical and chemical measurements stimulated the determination of accurate atomic weight. 4. Until the discovery of the subatomic particles, the structure of atoms was not fully understood. 5. These laws (the laws of the Conservation of Mass and Definite Proportions) were an important stimulation for the 19th-century chemistry. 6. The first period in the development of chemistry is the ancient period (until 350 A. D.). 7. There are five periods in the history of chemistry. 8. Mendeleyev’s law of periodicity of elements has withstood the onslaught of the discovery of the subatomic particles. 9. Five “elements” (earth, air, fire, water and the quintessence) were considered by the ancients as the building blocks of matter.
b) 1. Is your text difficult? — It is easy. 2. Was the philosopher’s stone found? — No, it was not. 3. What is this? — It is a text-book. 4. Whose book is it? — It is Nick’s book. 5. It is a very interesting phenomenon. 6. It is winter. 7. It is snowing now. 8. It was early morning when we came to the laboratory. 9. It is a long way from our hostel to die university. 10. It is believed that Wohler synthesized urea in 1828. 11. During the phlogiston period it was considered that some hypothetical matter was required for combustion and calcination. 12. It is necessary to know the periodicity in the history of chemistry. 13. It is never too late to leam. 14. It is chemistry that is my favourite subject. 15. It was Lomonosov who was the founder of Russian physico-chemical science. 16. It was early in the 19th century that Dalton founded his atomic theory. 17. It was after urea was synthesized that the development of organic chemistry was stimulated. 18. It was not the alchemical period which was the shortest in the history of chemistry. 19. It was not until qualitative and quantitative analysis had identified enough pure substances that inorganic chemistry grew in scope. 20. It was not until 1808 that Gay-Lussac’s law was postulated. 21. Theirs was a very important discovery. 22. Ours is a most essential science. 23. These are the latestjournals. 24. Accurate measurements began with the laws of Boyle, Charles, Gay-Lussac and Dalton. These stimulated the efforts to determine accurate atomic weights. 25. How can one prepare urea? 26. One can express the idea for combination in valence. 27. Why does one call Mendeleyev’s law the periodic law? 28. One must clearly understand the idea of chemical transformation. 29. One should be accurate in laboratory measurements.
Ex. 10. Translate the sentences into English.
1. Kimyo taraqqiyoti tarixida bir necha davrlar mavjud. 2. Hatto Qadimgi Yunonistonda ham materiyani o'rganishga falsafiy yondoshilgan. 3. Shuni esda tutish kerakki, alximiklar davrining asosiy maqsadi faylasufning toshini qidirish edi. 4. Bu faylasufning toshini oddiy metallarni oltinga aylantiradi deb ishonishgan. 5. Faqat miqdoriy va sifat tahlil qilish usullari ishlab chiqilganida, yetarli miqdordagi toza moddalarni olish mumkin bo'ldi. 6.Kalsinatsiya paytida metallar og'irligining ortishi keyinchalik gazlarning kashf qilinishiga olib keldi. 7. Sifat analizi nima? 8. 1928 yilgacha organik kimyo haqida juda kam bilishgan. 9. Ko'pgina olimlar o'zlarining atom tuzilish modellarini yaratdilar.
Ex. 11. Answer the following questions:
1. How many periods are there in the history of chemistry? 2. What are these periods? 3. What do you know about the ancient period? 4. What were the principal goals o f the alchemical period? 5. What was the period of iatrochemistry devoted to? 6. Why is the period between 1650 and 1774 called .the phlogiston period? 7. When does modem chemistry begin?8. What stimulated the development of chemistry in the 19th century?9. What investigations led to the discovery of the Periodic Law?
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