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Chemistry · Structure of atom
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Chemistry · Structure of atom
Given below are two statements:\n Statement I: The 4s orbital has a lower \( (n + l) \) value than the 3d orbital, hence 4s fills before 3d.\n Statement II: Valence electrons are those electrons added to the electronic shell with the lowest principal quantum number. \nIn the light of the above statements, choose the most appropriate answer from the options given below:
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If the radius of a nucleus of a heavy atom \( A \) is estimated, what is the approximate ratio of the nuclear radius to the radius of its atom if the atomic radius is of the order of \( 10^{-10}\text{ m} \) and nuclear radius is \( 10^{-14}\text{ m} \)?
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What is the energy associated with the first orbit in the hydrogen atom given by \( E_1 = -2.18 \times 10^{-18} \text{ J atom}^{-1} \)? What is the energy associated with the fifth orbit?
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Match List-I with List-II: List-I List-II A J.J. Thomson I Oil drop method for charge B R.A. Millikan II Discovery of neutron C James Chadwick III Measurement of \( e/m_e \) ratio D Ernest Rutherford IV Nuclear model of atom Choose the correct answer from the options given below:
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Macroscopic objects in our daily life do not show wave-like properties. Reason (R): The wavelengths associated with macroscopic objects are extremely short because of their large mass. In the light of the above statements, choose the correct answer from the options given below:
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).\n Assertion (A): The energy of the orbitals in a hydrogen atom depends solely on the principal quantum number \( n \).\n Reason (R): In a hydrogen atom, the 2s and 2p orbitals have exactly the same energy. \nIn the light of the above statements, choose the correct answer from the options given below:
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An atom of an element contains \( 29 \) electrons and \( 35 \) neutrons. Deduce the number of protons and the atomic number of the element.
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Calculate the frequency of the radiation emitted when an electron jumps from the \( n = 5 \) state to the \( n = 2 \) state in a hydrogen atom (\( R_H = 2.18 \times 10^{-18} \text{ J} \), \( h = 6.626 \times 10^{-34} \text{ J s} \)).
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Given below are two statements:\n Statement I: The energy of an orbital in a multi-electron atom depends on both principal quantum number \( n \) and azimuthal quantum number \( l \).\n Statement II: In a hydrogen atom, the 3s, 3p, and 3d orbitals all possess different energies. \nIn the light of the above statements, choose the most appropriate answer from the options given below:
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).\n Assertion (A): The orbital wave function \( \psi \) itself has no physical meaning.\n Reason (R): The square of the wave function \( |\psi|^2 \) at any point gives the probability density of the electron at that point. \nIn the light of the above statements, choose the correct answer from the options given below:
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Consider the following statements related to atomic structure and sub-atomic particles: (I) J.J. Thomson proposed that the positive charge is uniformly distributed in a sphere with electrons embedded in it. (II) Rutherford's nuclear model accounts for the solar-system-like circular motion of electrons around the dense nucleus. (III) The charge on an electron was precisely measured by J.J. Thomson using cathode ray deflection. (IV) Isotopes share identical chemical properties due to having the same number of electrons and protons. Which combination of statements is correct?
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A cathode ray tube operates at a high voltage in a partially evacuated glass tube. In the absence of external fields, what is the nature of the path traveled by the cathode rays?
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Calculate the wavelength of a light wave whose period is \( 2.0 \times 10^{-10} \text{ s} \).
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Given below are two statements:\n Statement I: Aufbau principle dictates that electrons fill orbitals in order of increasing energies.\n Statement II: Hund's rule states that pairing of electrons in orbitals belonging to the same subshell does not take place until each orbital is singly occupied. \nIn the light of the above statements, choose the most appropriate answer from the options given below:
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What is the relative charge of an electron?
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Which of the following fundamental equations in quantum mechanics represents the Schrödinger wave equation involving the Hamiltonian operator \( \hat{H} \)?
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What is the primary reason why subshells within the same principal shell possess different energies in multi-electron atoms?
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What is the wavelength of a photon emitted during a transition from \( n = 5 \) state to the \( n = 2 \) state in a hydrogen atom?
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Cathode rays travel in straight lines in the absence of an electrical or magnetic field. Reason (R): Cathode rays consist of negatively charged particles called electrons. In the light of the above statements, choose the correct answer from the options given below:
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If the wavenumber of a spectral line in the Paschen series of hydrogen spectrum is \( 9.139 \times 10^3 \text{ cm}^{-1} \), calculate the higher principal quantum number \( n_2 \) from which the electron transition takes place (\( R_H = 109677 \text{ cm}^{-1} \)).
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Calculate the wavelength of light emitted when an electron in a hydrogen atom undergoes transition from an energy level with \( n = 4 \) to an energy level with \( n = 2 \).
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What is the total number of nodes (radial + angular) for a \( 4p \) orbital?
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