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Showing posts with the label XI Chemistry


CHAPTER # 3 ATOMIC STRUCTURE Introduction The theory explains that matter was made from small indivisible particles called atoms. According to ancient era, this theory was put on a sound scientific basis by John Dalton in 1808. Dalton’s Concept In early 1800s, John Dalton proposed his theory that matter was composed of minute discrete particles called atoms (Greek = indivisible). Recent Concept Today, it is well established that atoms are complex organization of matter and energy. Many particles have been discovered within the atom. These sub atomic particles include electron, proton, neutron, several types of mesons, hyprons, etc. Evidence for the presence of electrons, protons and neutrons in the atom is derived through the experiment. FARADAY’S EXPERIMENT   Passage of Electricity through Solutions  Clue about Electrons   In this experiment, Faraday’s passed electricity through an electrolytic solution. He observed that when two  metal plates (electrodes) are placed in an