I. Multiple Choice Questions (Type-I)
1. Which of the following conclusions could not be derived from Rutherford’s
α -particle scattering experiement?
(i) Most of the space in the atom is empty.
(ii) The radius of the atom is about 10–10 m while that of nucleus is 10–15 m.
(iii) Electrons move in a circular path of fixed energy called orbits.
(iv) Electrons and the nucleus are held together by electrostatic forces of
attraction.
2. Which of the following options does not represent ground state electronic
configuration of an atom?
(i) 1s2 2s2 2p6 3s2 3p6 3d8 4s2
(ii) 1s2 2s2 2p6 3s2 3p6 3d9 4s2
(iii) 1s2 2s2 2p6 3s2 3p6 3d10 4s1
(iv) 1s2 2s2 2p6 3s2 3p6 3d5 4s1
3. The probability density plots of 1s and 2s orbitals are given in Fig. 2.1:
1s 2s
Fig. 2.1
The density of dots in a region represents the probability density of finding
electrons in the region.
16-04-2018
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, On the basis of above diagram which of the following statements is incorrect?
(i) 1s and 2s orbitals are spherical in shape.
(ii) The probability of finding the electron is maximum near the nucleus.
(iii) The probability of finding the electron at a given distance is equal in all
directions.
(iv) The probability density of electrons for 2s orbital decreases uniformly
as distance from the nucleus increases.
4. Which of the following statement is not correct about the characteristics of
cathode rays?
(i) They start from the cathode and move towards the anode.
(ii) They travel in straight line in the absence of an external electrical or
magnetic field.
(iii) Characteristics of cathode rays do not depend upon the material of
electrodes in cathode ray tube.
(iv) Characteristics of cathode rays depend upon the nature of gas present
in the cathode ray tube.
5. Which of the following statements about the electron is incorrect?
(i) It is a negatively charged particle.
(ii) The mass of electron is equal to the mass of neutron.
(iii) It is a basic constituent of all atoms.
(iv) It is a constituent of cathode rays.
6. Which of the following properties of atom could be explained correctly by
Thomson Model of atom?
(i) Overall neutrality of atom.
(ii) Spectra of hydrogen atom.
(iii) Position of electrons, protons and neutrons in atom.
(iv) Stability of atom.
7. Two atoms are said to be isobars if.
(i) they have same atomic number but different mass number.
(ii) they have same number of electrons but different number of neutrons.
(iii) they have same number of neutrons but different number of electrons.
(iv) sum of the number of protons and neutrons is same but the number of
protons is different.
8. The number of radial nodes for 3p orbital is __________.
(i) 3
(ii) 4
(iii) 2
(iv) 1
15 Structure of Atom
16-04-2018
Click on this link to buy latest Educart Books on Amazon - https://amzn.to/399Osrj
I. Multiple Choice Questions (Type-I)
1. Which of the following conclusions could not be derived from Rutherford’s
α -particle scattering experiement?
(i) Most of the space in the atom is empty.
(ii) The radius of the atom is about 10–10 m while that of nucleus is 10–15 m.
(iii) Electrons move in a circular path of fixed energy called orbits.
(iv) Electrons and the nucleus are held together by electrostatic forces of
attraction.
2. Which of the following options does not represent ground state electronic
configuration of an atom?
(i) 1s2 2s2 2p6 3s2 3p6 3d8 4s2
(ii) 1s2 2s2 2p6 3s2 3p6 3d9 4s2
(iii) 1s2 2s2 2p6 3s2 3p6 3d10 4s1
(iv) 1s2 2s2 2p6 3s2 3p6 3d5 4s1
3. The probability density plots of 1s and 2s orbitals are given in Fig. 2.1:
1s 2s
Fig. 2.1
The density of dots in a region represents the probability density of finding
electrons in the region.
16-04-2018
Click on this link to buy latest Educart Books on Amazon - https://amzn.to/399Osrj
, On the basis of above diagram which of the following statements is incorrect?
(i) 1s and 2s orbitals are spherical in shape.
(ii) The probability of finding the electron is maximum near the nucleus.
(iii) The probability of finding the electron at a given distance is equal in all
directions.
(iv) The probability density of electrons for 2s orbital decreases uniformly
as distance from the nucleus increases.
4. Which of the following statement is not correct about the characteristics of
cathode rays?
(i) They start from the cathode and move towards the anode.
(ii) They travel in straight line in the absence of an external electrical or
magnetic field.
(iii) Characteristics of cathode rays do not depend upon the material of
electrodes in cathode ray tube.
(iv) Characteristics of cathode rays depend upon the nature of gas present
in the cathode ray tube.
5. Which of the following statements about the electron is incorrect?
(i) It is a negatively charged particle.
(ii) The mass of electron is equal to the mass of neutron.
(iii) It is a basic constituent of all atoms.
(iv) It is a constituent of cathode rays.
6. Which of the following properties of atom could be explained correctly by
Thomson Model of atom?
(i) Overall neutrality of atom.
(ii) Spectra of hydrogen atom.
(iii) Position of electrons, protons and neutrons in atom.
(iv) Stability of atom.
7. Two atoms are said to be isobars if.
(i) they have same atomic number but different mass number.
(ii) they have same number of electrons but different number of neutrons.
(iii) they have same number of neutrons but different number of electrons.
(iv) sum of the number of protons and neutrons is same but the number of
protons is different.
8. The number of radial nodes for 3p orbital is __________.
(i) 3
(ii) 4
(iii) 2
(iv) 1
15 Structure of Atom
16-04-2018
Click on this link to buy latest Educart Books on Amazon - https://amzn.to/399Osrj
