Atomic Structure PDF

of In pos 1911, Ernest Rutherford discovered the nucleus, which Is preaent in the ceitYe Ot an atom. According to Rutherford's nuclear model of the atom, the atom con...

of In pos 1911, Ernest Rutherford discovered the nucleus, which Is preaent in the ceitYe Ot an atom. According to Rutherford's nuclear model of the atom, the atom consists of a centre and the electrons revolve around it in Jud in small, heavy positively-charged nucleus at the the planets revolve around the sun. revolve around the nucleus in circular paths ike model, electrons to Bohr's fixed o According atomic ot definite amount of energy. Shells are also called energy levels orbits or shells that have electrically neutral particle called Chadwick discovered the In 1932, Jarmes neutron presernt in the nucleus. neutrons (collecctively called the contains protons and The nucleus of an atomn are present in the extra-nuclear region, present in the nucleus of an atom of an element is nucleons). Electrons " The number of protons number of the element. known as the atormic the nucleus of an and neutrons present in atorm is called the mass nurmber The sum of the protons of the atom. electrons that can be accommodated in an energy level of an aton is The maximum number of given by the formula 2n', where n is the number of the shell. accommodate more than 8 The outermost shell of an atom cannot capacity to accommodate more electrons. electrons, even if it has the Keywords NUCLEUS a positively-charged core in the centre of an atom where the mass of atom is concentrated the ELECTRONIC cONFIGURATION the arrangement of electrons in different shells the VALENCE SHELL the outermost shell of an atom atoms of an element Exercises A. Tick the most 1, Which of the appropriate iswer. à. John Dalton following scientists observed that cathode rays consist of b. J. Thomson c. E. Goldstein negatively-charged particles? d. James Chadwick realme 11x 5G 2024.10.10 18:54  gutherford's alpha scattering experinent led to the discovery of which of the following? Muckeis b. electrons. protons d. neutrons hatis an electrode connected to thc ncgative terminal of a voltage sOurce called! cathode b. neutron. anode d. proton atis an electrode connected to the positive terrninal of a voltage source called? 4 cathode b. neutron. anode d. proton.uhat is the positively-charged core in the centre of an atom called? 2 neutron b. anode C. proton d. nucleus 6 Whichof the following symbols represents the atomic number of an elernent? b. p C. e d. A zhichof the following is not present in a hydrogen atom? 2 proton b. peutron G. nucleus d. electron hat is the maximum nunmber of electrons that can be accommodated by the M shel? a. 2 b. 8 C. 18 d. 32 e Fill in the blanks..An electron carries a charge. , An atom is electrically i The mass of a is equal to that of hydrogen.. The paths along which electrons revolve around the nucleus are called has mass approximately equal to that of a proton..The number of protons present in the nucleus of an atorn is known as its 1 The outermost shell of an atom is also called the /J shel. iWrite true or false.Correct the false statements.. Maharshi Kanada named the smallest particle of matter anu. 2 All atoms of an elernent differ from each other. Atoms of different elements combine in fixed,small whole-nurnber ratios to form LAn electrode connected to the negative terminal of a voltage source is cálled compounds. s An electron is considered nearly rmassless. the anode. 6. The positive charge of the nucleus is due to the 1. The er of, protons present in the neutrons present in it. a nucleus of an atom is known as its mass Thomson.proposed that the nucleus of an atom contains protons and neutrons. nurnber. D. Name the following. Asubatonic particle that carries a The model that states the atom is anegative charge ) i iy inside it sphere of positive chartes ánd the electrons are spreo  3. All the mass of an atom is concentrated in it /l 4. A subatomic partlcle that is elcctrically neutral 5. Arrangement of clectrons in different shells of an atom V ) 6. The outermost shell of an atom E. Match the columns.. J. J. Thomson ? proton 2. Ernest Rutherford ) b. neutron 3. James Chadwick h c. atomic theory 4. John Dalton c d. nucleus 5. E. Goldstein electron F. Answer the following in short. What are cathode rays? What is (the nature of charge on cathode rays? 2. Name the three subatomicparticles of an atom. Write their syrmbols and charges. 3 What is a proton? How does it differ from a neutron? 4. What are shells? Write the maximum number of electrons that they can accormmodate. 5. How is an element symbolically represented? 6. Differentiate between the atomic number and the mass number. 7. From the symbol $X, identify the element and write down its mass numb number. G. Answer the following in detail. x State the principal ideas of Dalton's atomic theory. 2. Describe Thomson's plum pudding model. Which subatomic particle was not pre ent in tib model of the atom? 2(t Mty, :. State Rutherford's observations based on his alpha-scattering a! he draw from the observations? experiment. What conusions id Describe Rutherford's nuclear model of the atom. Describe Bohr's atomic model. What is the Bohr-Bury scheme of electronic configuration? Write observed according to the scheme for writing the number of levels or shells. Explain howthe electrons are arranged in the shells of a potassum atom. raw diagrams of the following. utherford's alpha-scattering experiment bhr's atomic model