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Structure of the Atom

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  INTRODUCTION Matter is made up of tiny particles called atoms. Atoms are further made of three fundamental particles or sub тАУ atomic particles called electron, proton and neutron. Earlier Dalton postulated that atom is indivisible i.e. cannot be further divided which proved to be wrong by discovery of sub тАУ atomic particles. Types of Sub - atomic Particles Note - Protons and neutrons are almost of same mass.The mass of proton is approximately 2000 times as that of the electron. Discovery of Sub- atomic Particles (a) Electron (e - ): These negatively charged particles were discovered by J. J. Thomson in 1897. In the experiment, a gas at low pressure was taken in a discharge tube made up of glass. At the ends of the discharge tube two electrodes were placed, connected to a battery for high voltage supply. The electrode connected to the negative end was known as cathode and that to the positive as anode. He then observed a stream of negatively charged particle...

Adolescent brain makes learning easier: Study

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LONDON: The brains of adolescents react more responsively to receiving rewards, according to a study that shows it can make learning easier. "The  adolescent brain  is very sensitive to feedback. That makes adolescence the ideal time to acquire and retain new information," said  Sabine Peters , from the  Leiden University  in the Netherlands. Researchers used a large data set for her research with MRI scans. Over a period of five years, no fewer than 736 brain scans were made of a total of 300 subjects between the ages of 8 and 29. According to Peters, the data set is about ten times larger than that of most comparable studies. In the MRI scanner, the participants had to solve a memory game. During that game, the researchers gave feedback on the participants' performance. The study was published in the journal  Nature Communications . "It showed that adolescents responded keenly to educational feedback," said Peters. "If the adolescent received usef...

Story of the nebula

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A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases in a galaxy. The Persian astronomer, Abd al-Rahman al-Sufi, mentioned a true nebula for the first time in his book, Book of Fixed Stars (964). He said that there was a "little cloud" near the Andromeda galaxy. A nebula is usually made up of hydrogen gas and plasma. It may be the first stage of a star's cycle, but it may also be one of the last stages. Many nebulae or stars form from the gravitational collapse of gas in the interstellar medium or ISM. As the material contracts, massive stars may form in the center, and their ultraviolet radiation ionises the surrounding gas, making it visible at optical wavelengths. The size of these nebulae, known as H II regions, varies depending on the size of the original cloud of gas. These are sites where star formation occurs. The formed stars are sometimes known as a young, loose cluster. Some nebulae are formed as the result of supernova ex...

Scientists 'inject' information into monkeys' brains

Scientists 'inject' information into monkeys' brains In an experiment with science fiction implications, two neuroscientists say they have managed to introduce information directly into the premotor cortex of monkeys. PHOTO CREDIT: Christoph Hitz/NYT When you drive towards an intersection, the sight of the light turning red will make you step on the brake. This action happens due to a chain of events inside your head. Your eyes relay signals to the visual centres in the back of your brain. After those signals get processed, they travel along a pathway to another region, the premotor cortex, where the brain plans movements. Signalling the brain Now, imagine that you had a device implanted in your brain that could shortcut the pathway and 'inject' information straight into your premotor cortex. That may sound like an outtake from The Matrix. But now two neuroscientists at the University of Rochester, USA say they have managed to introduce information directly into...

рдореЗрдШ рдЖрдпреЗ

рдореЗрдШ рдЖрдпреЗ рдкрд╛рда рдХрд╛ рд╕рд╛рд░ рдЗрд╕ рдХрд╡рд┐рддрд╛ рдореЗрдВ рдореЗрдШреЛрдВ рдХреЗ рдЖрдиреЗ рдХреА рддреБрд▓рдирд╛ рд╕рдЬрдХрд░ рдЖрдП рдкреНрд░рд╡рд╛рд╕реА рдЕрддрд┐рдерд┐ рджрд╛рдорд╛рдж) рд╕реЗ рдХреА рд╣реИред рдЧреНрд░рд╛рдореАрдг рд╕рдВрд╕реНрдХреГрддрд┐ рдореЗрдВ рджрд╛рдорд╛рдж рдХреЗ рдЖрдиреЗ рдкрд░ рдЙрд▓реНрд▓рд╛рд╕ рдХрд╛ рдЬреЛ рд╡рд╛рддрд╛рд╡рд░рдг рдмрдирддрд╛ рд╣реИ , рдореЗрдШреЛрдВ рдХреЗ рдЖрдиреЗ рдХрд╛ рд╡рд░реНрдгрди рдХрд░рддреЗ рд╣реБрдП рдХрд╡рд┐ рдиреЗ рдЙрд╕реА рдЙрд▓реНрд▓рд╛рд╕ рдХреЛ рджрд┐рдЦрд╛рдпрд╛ рд╣реИред рдХрд╡рд┐ рдиреЗ рдореЗрдШреЛрдВ рдХреА рддреБрд▓рдирд╛ рд╕рдЬрдХрд░ рдЖрдП рдЕрддрд┐рдерд┐ (рджрд╛рдорд╛рдж) рд╕реЗ рдХрд░рддреЗ рд╣реБрдП рдХрд╣рд╛ рд╣реИ рдХрд┐ рдореЗрдШ рд╢рд╣рд░ рд╕реЗ рдЖрдП рдЕрддрд┐рдерд┐ рдХреА рднрд╛рдБрддрд┐ рд╕рдЬ-рдзрдЬ рдХрд░ рдЖрдП рд╣реИрдВред рдЬрд┐рд╕ рддрд░рд╣ рдореЗрд╣рдорд╛рди рдХреЗ рдЖрдиреЗ рдкрд░ рдЧрд╛рдБрд╡ рдХреЗ рд▓реЬрдХреЗ-рд▓реЬрдХрд┐рдпрд╛рдБ рднрд╛рдЧ рдХрд░ рд╕рдмрдХреЛ рдЗрд╕рдХреА рд╕реВрдЪрдирд╛ рджреЗрддреЗ рд╣реИрдВ, рдЙрд╕реА рддрд░рд╣ рдореЗрдШ рдХреЗ рдЖрдиреЗ рдХреА рд╕реВрдЪрдирд╛ рджреЗрдиреЗ рдХреЗ рд▓рд┐рдП рд╣рд╡рд╛ рддреЗреЫ рдЧрддрд┐ рд╕реЗ рдмрд╣рдиреЗ рд▓рдЧреА рд╣реИред рдореЗрд╣рдорд╛рди рдХреЛ рджреЗрдЦрдиреЗ рдХреЗ рд▓рд┐рдП рдЬрд┐рд╕ рддрд░рд╣ рд▓реЛрдЧ рдЦрд┐реЬрдХреА-рджрд░рд╡рд╛рдЬреЛрдВ рд╕реЗ рдЭрд╛рдБрдХрддреЗ рд╣реИрдВ, рдЙрд╕реА рддрд░рд╣ рдореЗрдШреЛрдВ рдХреЗ рджрд░реНрд╢рди рдХреЗ рд▓рд┐рдП рднреА рд▓реЛрдЧ рдЙрддреНрд╕реБрдХрддрд╛рдкреВрд░реНрд╡рдХ рдЦрд┐реЬрдХреА-рджрд░рд╡рд╛рдЬреЛрдВ рд╕реЗ рдмрд╛рд╣рд░ рдЖрдХрд╛рд╢ рдХреА рддрд░реЮ рджреЗрдЦрдиреЗ рд▓рдЧреЗ рд╣реИрдВред рдЗрд╕ рддрд░рд╣ рдЫреЛрдЯреЗ-рдмреЬреЗ, рдХрд╛рд▓реЗ-рднреВрд░реЗ-рд╕рдлреЗрдж рд░рдВрдЧ рдХреЗ рдореЗрдШ рдЕрдкрдиреЗ рджрд▓-рдмрд▓ рдХреЗ рд╕рд╛рде рдЖрдХрд╛рд╢ рдореЗрдВ рдРрд╕реЗ рдЫрд╛ рдЧрдП рд╣реИрдВ рдорд╛рдиреЛ рдХреЛрдИ рд╢рд╣рд░реА рдореЗрд╣рдорд╛рди рд╕рдЬ-рдзрдЬ рдХрд░ рдЧрд╛рдБрд╡ рдореЗрдВ рдЖрдпрд╛ рд╣реЛред рдЬрд┐рд╕ рддрд░рд╣ рдореЗрд╣рдорд╛рди рдХреЗ рдЖрдиреЗ рдкрд░ рдЧрд╛рдБрд╡ рдХреЗ рд╡реГрджреНрдз рдЖрдЧреЗ рдЖрдХрд░ рдФрд░ рд╣рд╛рде рдЬреЛреЬрдХрд░ рдЕрддрд┐рдерд┐ рдХрд╛ рдЖрджрд░ рд╕рддреНрдХрд╛рд░ рдХрд░рддреЗ рд╣реИрдВ рддрдерд╛ рдкрддреНрдиреА рджреАрд╡рд╛рд░ рдХреА рдУрдЯ рд▓реЗрдХрд░ рджреЗрдЦрддреА рд╣реИрдВ рдЙрд╕реА рддрд░рд╣ рдЖрдХрд╛рд╢ рдореЗрдВ рдмрд╛рджрд▓реЛрдВ рдХреЗ рдЫрд╛ рдЬрд╛рдиреЗ рдкрд░ рдЖрдБрдзреА рдЪрд▓реА рдЬрд┐рд╕рд╕реЗ рдмреВреЭреЗ рдкреАрдкреЗрд▓ рдХреЗ ...