14. 1) Scan the biography of Sir William Crookes. Pay attention to the underlined words and notions. Say or write what you know about them.

Sir William Crookes, (17 June 1832 – 4 April 1919) was an English chemist and physicist. Sir William attended the Royal College of Chemistry, in London, and worked on spectroscopy.

In 1861, Crookes discovered a previously unknown element with a bright green emission line in its spectrum and named the element thallium. Crookes also identified the first known sample of helium. He was the inventor of the Crookes radiometer, which today is made and sold as a novelty item. He also developed the Crookes tubes, investigating canal rays. He was a pioneer in the construction and use of vacuum tubes for the study of physical phenomena. He was, as a consequence, one of the first scientists to investigate what are now called plasmas. He also devised one of the first instruments for the study of nuclear radioactivity, the spinthariscope.

After 1850, he lived at 7 Kensington Park Gardens, where in his private laboratory all his later work was carried out. The breadth of his interests, ranging over pure and applied science, economic and practical problems, and psychical research, made him a well-known personality, and he received many public and academic honours. In 1859 he founded the Chemical News a science magazine, which he edited for many years and conducted on much less formal lines than is usual with journals of scientific societies. Crookes was knighted in 1897, and in 1910 received the order of merit. Crookes was always more effective in experiment than in interpretation.

14. 2) Scan the biography of John Dalton. Put questions to the given answers.

John Dalton was born September 6, 1766, in England and died July 27, 1844, in Manchester. A chemist and physicist, he developed the atomic theory of matter and hence is known as one of the fathers of modern physical science. Dalton spent most of his life in Manchester. He began his studies of meteorology in 1787. He made valuable observations concerning, the trade winds, and the cause of rain. He determined the point of the maximum density of water. In chemistry, his major work began around 1800.

Dalton developed the law known as Dalton's Law of partial pressures. Dalton's Law states that the total pressure of gas is equal to the sum of the partial pressures of the individual component gasses. The partial pressure is the pressure that each gas would exert if it, alone, occupied the volume of the mixture at the same temperature. This empirical relation was stated in 1801. It follows from the kinetic theory of gasses under the assumption of a perfect (ideal) gas, and assumes no chemical interaction between the component gasses. It is approximately valid for real gasses at sufficiently low pressures and high temperatures.

He also found that gasses expand as their temperature is raised. Further experiments showed the solubility of gasses in water, the rate of diffusion of gases, and the constancy of composition of the atmosphere. Dalton determined the relative weights of atoms, developed the laws of definite and multiple proportions, and finally formulated the atomic theory, which states that all elements are composed of tiny, identical, and indestructible particles. Many of these findings were included in the New System of Chemical Philosophy.

1. --------------------------- In England.

2. --------------------------- No, he was a chemist and physicist.

3. --------------------------- Physical science.

4. --------------------------- He developed the law of partial pressures.

5.---------------------------- Yes, he formulated the atomic theory.

6.---------------------------- The New System of Chemical Philosophy.