George Karl von Hevesy (1885 - 1966)

Name: George Karl von Hevesy
DOB: 1885

Died: 1966.
Discoveries: Hafnium in 1922.

Hevesy was born in Budapest,Hungary and naturalized himself to become a Swedish. He died in Friburgh in 1966.
He was privileged to study in Budapest,Berlin and Friburgh and was teacher in Budapest,Copenhangen,Friburgh and Stockholm. With Dutch D. Coster, he began the research work that lead him to the discovery of Hafnium in 1922.

He also studied its compounds as well as the elements usually called rare-earths. He also devoted some time to biochemistry and above all, to radioactivity.

Hevesy was granted the Nobel Prize of Chemistry in 1943 for his work on Isotopes and the chemical properties of substances.

Gustav Robert Kirchoff (1824 - 1887)

Name: Gustav Robert Kirchoff

DOB: 1824

Died:  1887
Discoveries: accomplished studies on the theory of electrical circuits

G.R.K, a German born physicist was born in Koenigsberg,in 1824 and died in Berlin in the year 1887.

His more notable scientific works were in the domain of thermal radiation and of spectral analysis. He was responsible for the discovery in 1861 together with Bunsen,of the rubidium and cerium;this work enabled the first explanation of the absorption stripes usually called Fraunhofer stripes.

He also accomplished studies on the theory of electrical circuits.

He was a physics professor at the University of Heidelberg. In 1874, he went to the University of Berlin and became member of the science Academy.

Friedrich Wohler (1800 - 1882)

Friedrich Wohler Preview:

Name: Friedrich Wohler
DOB: 1800

Died: 1882.
Discoveries: Isolated Aluminium,Beryllium and obtained Urea.

Wohler, the German Chemist was birthed in Eschersheim in the year 1800 and died after 82 years in Goettingen in the year 1882.

He was once a professor at the University of Goettinghen.
He obtained Urea for the very first time in the history of man in 1828 through the synthesis of ammonia compounds. This idea however,was contradictory to what was been used at that time for the synthesis of Organic compounds.

 However,he did it again in 1827 and 1828 when he Isolated aluminium and beryllium respectively for the first time in the history of man.

Francis William Aston ( 1877 - 1945)

Ok today, lets take a qucik look at the scientist we have got on file:

 

Name: Francis William Aston.
DOB: 1/Sept/1877
Died: 20/Nov/1945
Discoveries: Worked on Isotopes and its constituents.
Nobel Prize: 1922. Nobel Prize of Chemistry.

Francis W. Aston was an experimental physicist who was born in Harborne,England on the first day of September 1877 and died on the 20th of November 1945 in Cambridge.

He was privilege to work with :

* Frankland ---- 1898
* Poynting ----- 1903
* J.J Thomson ----- 1910

He had a vast and enormous experiences in vacuum techniques that made possible the evidence of the Isotopic Constitution of stable element. In 1913, he accomplished the partial separation of Isotopes by the method of diffusion.

In 1922, Francis received the Nobel Prize of Chemistry. For a full knowledge of his work, consult his book titled "Mass Spectra and Isotopes" (1942)

Carl william Scheele (1742 - 1786)

Carl Wilhelm Scheele (1742 - 1786)

Lets take a quick look at who we've got on our list of great scientists today:

Name: Carl Wilhelm Scheele
DOB: 9th/Dec/1742
Died: 21st/May/1786
Discovery: Manganese dioxide Analysis (let to Chlorine and Barite discoveries.)

 Carl Wilhelm Scheele to history was a Sweedish Chemist who was born in Stralsund in the year 1742 and died in Koping on the 21st day of May in the year 1786.
Carl was basically interested in the various themes of pure chemistry, especially because of his 28 years of close friendship with Bergman.

Carl Wilhelm Scheele was called in 1775 as a member of the Science Academy of Stockholm (oh! that's a big Academy. I am also dreaming of one as a scientist too). In the same year, Frederic the great tried to pull him to continue his studies at any University in London or better still,close up at Berlin but refused and decided to settle down with his own pharmacy at Koping, where most of his original works was accomplished.
In 1774, Carl analyzed the Manganese oxide which lead the way through to the discovery of Chlorine and Barite and some other descriptions of Manganese compounds.

Chlorine.

A common sense will flash us back to NaCl when we talk about Chlorine. But we did rather say Chlorine ia a heavy yellow irritating toxic gas  belonging to the Halogen family. It is used to purify water and also serve as a bleaching agent and a disinfectant.
It is the chemical element with atomic number 17 and Cl as symbol.

Barite.

Barite isn't a common element to common science students in this part of the world but we all learnt that barite is an heavy spar,white,colourless,light blue,light yellow or light red in colour. It can be used in the medical arena as an inicator or as a paint pigment or lubricant when added to other compounds in the chemical industries.

Antoine-Henri Becquerel (1852 - 1908)

Antoine-Henri Becquerel (1852 - 1908)

 A quick look at our Star Scientist for today.

Name: Antoine-Henri Becquerel
DOB: 15/DEC/1852.
Died: 25/AUG/1908.
Discovery: Radioactivity of Uranium salt.
Nobel Prize: Yes (1903).

Antoine-Henri Becquerel was the son of Alexandre-Edmond. He was born in Paris on the 15th of December in the year 1852. After 56 years of stay on this planet earth, Antoine-Henri bidded farewell to earth.

He died on the 25th or August 1908. During his lifetime, Antoine-Henri was priviledge to study in the Ecole polytechnic and in the Natural History Museum. A spectacular deeds of this great physicist was the completion of the research work of his father and grandfather which lead to his discovering of the radioactivity of uranium salts in the year 1896 as record has it.

 However,the committee of the Nobel prize aware found him together with Pierre and Marie Curie fit to be honoured with the Nobel prize in the year 1903 for their tremendious contributions to the science world and for Becquerel's discovery in particular. As an active member of the French Science Academy,Antoine-Henri lived a life worth celebrated.

Radioactivity

Radioactivity is a process in which an unstable atomic nucleus release energy subatomic particles. Word of radioactivity is used to describe subatomic particles themselves. This phenomenon has been observed for heavy elements such as uranium and unstable isotopes, such as carbon-14.

The radioactivity was discovered in 1896 by French scientist Henri Becquerel, after which the unit is called the Becquerel radiation. Becquerel discovered that uranium salts could blacken the photographic plate is in the dark, even the barrier of the paper. Further experiments to distinguish between three different types of radiation - alpha particles, beta particles and gamma rays. It is positively charged, negatively charged, and neutral, respectively. United States, human exposure to radioactivity measured in rad, where rad is the 0.01 per joule of energy absorbed by tissue.

Uranium Salt

Uranium salt is a silver-white metallic chemical element of the actinide series of the periodic table with atomic number 92. Is the chemical symbol U. A uranium atom has 92 protons and 92 electrons, 6 valence electrons. The uranium core is attached between 141 and 146 neutrons, the creation of six isotopes, the most common of which are of U-238 (146 neutrons) and U-235 (143 neutrons). All isotopes are unstable and uranium is weakly radioactive. Uranium has the highest weight of the natural elements atomic second, lighter than the plutonium-244. Its density is about 70% higher than lead, but not as dense as gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and extracted uranium ore pitchblende.

Uranium is found in nature, such as uranium-238 (99.2742%) of uranium-235 (0.7204%), and a small amount of uranium-234 (0.0054%). Uranium is slowly by emitting an alpha particle. Half-life of uranium-238 is about 4.47 billion years and that uranium-235 is 704 million years, which makes them useful for dating the age of the earth.