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4. Structure of the Atom I. For question numbers 1 to 8, two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a). (b), (c) and (d) as given below :   (a) Both A and R are true and R is the correct explanation of the assertion. (b) Both A and R are true butRis not the correct explanation of the assertion.   (c) A is true but R is false.   (d) A Is false but R is true. (1 Mark) 1. Assertion (A) : Electrons, protons and neutral particles (neutrons) in an atom are called 'sub-atomic particles'. Reason (R) : According to John Dalton's atomic theory, an atom can be further subdivided into three fundamental 'sub-atomic partides'. 2. Assertion (A) : JJ. Thomson explained presence of electrons by cathode rays experiment. Reason (R) : Charge on an electron is equal to - 1.6 x 10"C and mass of the electron is 9.1 x 10 kg. ...

Multiple Choice Questions (MCQs) lay a strong foundation for students who want to score better marks in their exams. By attempting topic wise and chapter wise MCQs, students can immediately find out how well they understand a topic or chapter from their text books whether it is NCERT books or books from some other publications.                               The MCQs designed by CBSE  HUB ONLINE (AAPKA EDU-GUIDE) Online comprehensively cover the topics, sub-topics, and chapters taught by different educational boards including CBSE, BSEH, and NBSE. Attempting an MCQs test also helps improve your critical & analytical skills. After submitting their answers, students can instantly see the results including total questions, correct answers, incorrect answers, not attempted, and marks percentage. By looking at these results alone, students can dramatically improve their overall understanding of a chapter or t...

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SYNTHETIC MATERIALS Polymer:-   A  polymer is made of small units.The monomers combine end-to-end under certain condition to form a polymer. For example cellulose is a polymer of glucose while hemoglobin is a polymer of amino acids. Polymerization :-                                      The process of formation of polymer from a monomer is called polymerization. Polymers can be classified into three types ·          NATURAL, ·          SEMI- SYNTHETIC ·          SYNTHETIC   TYPES OF FIBRES Fibres are also Polymers, so they are of above three types. TYPES OF FIBRE EXAMPLES Natural Cotton, jute, Silk, wool Semi synthetic Rayon (viscous, cuprammonium and acetat...