All Exams  >   NEET  >   NCERT Based Tests for NEET  >   All Questions

All questions of Structure of Atom for NEET Exam

Can you explain the answer of this question below:The number of radial nodes for 3p orbital is __________.
A:3
B:4
C:2
D:1
The answer is d.

Krishna Iyer answered
► Number of radial nodes = n - 1 – 1
► For 3p orbital, n = 3 – 1 – 1 = 1
► Number of radial nodes = 3 – 1 – 1 = 1. 

The nucleus of a tritium atom, 3H, contains
  • a)
    three protons
  • b)
    three neutrons
  • c)
    two protons and one neutron
  • d)
    two neutrons and one proton
Correct answer is option 'D'. Can you explain this answer?

Hansa Sharma answered
Tritium (3H) is a radioactive isotope of hydrogen. The nucleus decays (by emitting an electron and an antineutrino), changing from a triton (one proton and two neutrons) to a 3He nucleus (two protons and one neutron).

Thomson’s plum pudding model explained:
  • a)
     Existence of electrons
  • b)
    Electrical neutrality of an atom
  • c)
    Existence of atoms
  • d)
    Electrons move in fixed circular orbits
Correct answer is option 'B'. Can you explain this answer?

Raghav Bansal answered
Postulates of Thomson’s atomic model
  • An atom consists of a positively charged sphere with electrons filled into it. The negative and positive charge present inside an atom are equal and as a whole, an atom is electrically neutral.
  • Thomson’s model of the atom was compared to plum pudding and watermelon. He compared the red edible part of the watermelon to positively charged sphere whereas the seeds of watermelon to negatively charged particles.

 Which of the following radiation has the shortest wavelength.
  • a)
    Infra red
  • b)
    ultraviolet
  • c)
    microwave
  • d)
    X-ray
Correct answer is option 'D'. Can you explain this answer?

Gaurav Kumar answered
Radio waves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma raysare all types of electromagnetic radiation. Radio waves have the longest wavelength, and gamma rays have the shortest wavelength.

Energy change associated per mole of atoms with an atomic transition giving rise to radiations of  What is the value of x?
    Correct answer is '4'. Can you explain this answer?

    Naina Sharma answered
    Energy = n.hv
    where,
    n = 1 mole or 6.023 × 1023 atoms
    h = 6.626×10-34 J.sec
    v (frequancy) = 1 Hz
    ⇒ E = 6.023 ×1023 × 6.626×10-34 × 1 = 3.91 × 10-10
    so approximately value of x = 4.

    The wavelength of light that has a frequency of 1.20 × 1013s-1 is __________ m.
    • a)
      2.50 × 10-5
    • b)
      0.0400
    • c)
      25.0
    • d)
      12.0
    Correct answer is option 'A'. Can you explain this answer?

    Krishna Iyer answered
     
    The speed of all form of electromagnetic wave is related by the equation c = λ.v, whereby, λ = 3.0 x 108 / 1.2 x 1013 = 2.5 x 10 -5 m.

    Direction (Q. Nos. 9-11) This section contains 3 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or  MORE THANT ONE  is correct.
    Q. Select the correct statement(s).
    • a)
      Electromagnetic radiation is a form of energy consisting of oscillating electric and magnetic fields
    • b)
      Visible light is a form of electromagnetic radiation
    • c)
      The electromagnetic spectrum of sunlight received at the Earth's surface differs from that emitted by the Sun
    • d)
      Ultraviolet radiation is absorbed in the stratosphere by ozone and oxygen
    Correct answer is option 'A,B,C,D'. Can you explain this answer?

    Geetika Shah answered
    Option A: Oscillations travel through space at a velocity of light, thus electromagnetic radiation is in the form of energy E = hv.
    Option B: Radiowaves, microwaves, X-rays, and visible light are part of the Electromagnetic radiation spectrum.
    Option C: Some of the radiations are absorbed in the atmosphere, hence the spectrum differs.
    Option D: Ozone layer absorbs ultraviolet radiation.
    Hence, options A, B, C, and D are correct.

     In the absorption spectrum, the wavelengths which are absorbed, are missing and they appear as:
    • a)
      Bright lines
    • b)
      Light bands
    • c)
      Bright bands
    • d)
      Dark lines
    Correct answer is option 'D'. Can you explain this answer?

    Riya Banerjee answered
    Light not absorbed by the sample will, as before, be separated (dispersed) into its component wavelengths (colors) by the prism. The appearance of the spectrum will resemble that obtained without the sample in place, with the exception that those wavelengths which have been absorbed are missing, and will appear as dark lines within the spectrum of colors. If a piece of the photographic film is used instead of the card, the absorption spectrum can be recorded.

     Whch of the following will have the maximum value of ∆v . ∆x
    • a)
      Cricket ball
    • b)
      Electron
    • c)
      Table
    • d)
      Tennis ball
    Correct answer is option 'B'. Can you explain this answer?

    Geetika Shah answered
    This is accordance with the Heisenberg's uncertainty principle.It states that it is not possible to accurately determine the position and momentum of a microscopic particle such as electron simultaneously.

    The energy associated with the transition of an electron from the n=1 state to the n=3 state of H atoms is:
    • a)
      +1.74 x 10-17 Joules.
    • b)
      -1.94 x 10-18 Joules.
    • c)
      +1.94 x 10-18 Joules.
    • d)
      -1.74 x 10-17 Joules.
    Correct answer is option 'C'. Can you explain this answer?

    Lavanya Menon answered
    The formula to calculate the excitation energy is 13.6Z2(1/n12-1/n22), but this gives value in eV. To convert it in Joules we divide it by 6.24×1018 Here, Z=1,n1=1,n2=3 Putting these values in above formula we have, [13.6×1(1-1/9)]/6.24×1018 =(13.6×8×10-18)/(9×6.24) =1.94×10-18 Hence, the correct answer is C.

    For Balmer series,the initial state n1 is :
    • a)
      4
    • b)
      2
    • c)
      3
    • d)
      1
    Correct answer is option 'B'. Can you explain this answer?

    Pooja Shah answered
    The Balmer series just sets n1 = 2, which means the value of the principal quantum number (n) is two for the transitions being considered. Balmer’s formula can therefore be written:
    1/λ = RH ((1/22) − (1 / n22))

    The number of radial nodes for 3p orbital is __________.
    • a)
      3
    • b)
      4
    • c)
      2
    • d)
      1
    Correct answer is 'D'. Can you explain this answer?

    Amrita Kumar answered
    Number of radial nodes = n-1 – 1
    For 3p orbital, n = 3 – 1 – 1 = 1
    Number of radial nodes = 3 – 1 – 1 = 1. 

    The nature of positive rays depends on?
    • a)
      The nature of discharge tube.
    • b)
      The nature of residual gas.
    • c)
      The nature of electrode.
    • d)
      All of above
    Correct answer is option 'B'. Can you explain this answer?

    Om Desai answered
    • The nature of positive rays produced in a vacuum discharge tube depends upon the nature of the gas-filled.
    • The positive rays consist of positive ions obtained by removing one or more electrons from gas molecules.

    The de – Broglie wavelength of an electron is 600 nm. The velocity of the electron having the mass 9.1 X 10-31 Kg is
    • a)
      0.0012 x 10+4 m/s
    • b)
      0.0012 x 10+3 m/s
    • c)
      0.0012 x 10+6 m/s
    • d)
      0.0012 x 10+2 m/s
    Correct answer is option 'C'. Can you explain this answer?

    Arjun Gupta answered
    1nm= 10^-9m.
    wavelength= 600nm= 600 ×10-9m
    wavelength= h/p.
    wavelength= h/mv
    v= h/ m wavelength
    v=6.625×10^-34/9.1×10^-31×600× 10-9.
    v= 6.625 × 10+4/9.1 ×6.
    v= 6.625× 10+4/9.1×6.
    v= 6.625 ×104/54.6.
    v= 0.12 × 104.
    v= 0.0012 × 10+6 .

    Which model describes that there is no change in the energy of electrons as long as they keep revolving in the same energy level and atoms remains stable?
    • a)
      Rutherford Model
    • b)
      Bohr’s Model
    • c)
      J.J Thomson Model
    • d)
      None of the above
    Correct answer is option 'B'. Can you explain this answer?

    Suresh Reddy answered
    Bohr Model of atom:
    • An atom is made up of three particles: Electrons, neutrons and protons.
    • The protons and neutrons are located in a small nucleus at the centre of the atom.
    • The electrons revolve rapidly around the nucleus at the centre of the atom.
    • There is a limit to the number of electrons that each energy level can hold.
    • Each energy level is associated with a fixed amount of energy.
    • There is no change in the energy of electrons as long as they keep revolving in the same energy level.
    Bohr explained the stability through the concept of revolution of electrons in different energy levels.
    The change in the energy of an electron occurs when it jumps from lower to higher energy levels. When it gains energy, it excites from lower to higher and vice versa.
    Thus energy is not lost and the atom remains stable.

    The nature of positive rays depends on?
    • a)
        The nature of discharge tube.
    • b)
        The nature of residual gas
    • c)
        All of above.
    • d)
        The nature of electrode
    Correct answer is option 'B'. Can you explain this answer?

    The positive charges in these rays, other than negative cathode rays (which are electrons), depend on the gas that is used because they are cations - atoms with mostly one electron missing and thus one positive charge. So, if you accelerate, argon cations and protons over the same electric potential, the particles in the rays will have the same kinetic energy, but the argon ions will be much slower, as they are much heavier than the protons.

    Zeeman effect is the splitting of spectral line in presence of:
    • a)
      electricity
    • b)
      magnetic effect
    • c)
      molecule
    • d)
      electric field
    Correct answer is option 'B'. Can you explain this answer?

    Lavanya Menon answered
    The Zeeman effect is the splitting of the spectral lines of an atom in the presence of a strong magnetic field. The effect is due to the distortion of the electron orbitals because of the magnetic field. The (normal) Zeeman effect can be understood classically, as Lorentz predicted. 

    Uncertainty in the position of an electron (mass 9.1 x 10-31 kg) moving with a velocity of 300 ms-1, accurate upto 0.001% will be:
    • a)
      1.92 x 10-2 m
    • b)
      3.84 x 10-2 m
    • c)
      19.2 x 10-2 m 
    • d)
      5.76 x 10-2 m
    Correct answer is option 'C'. Can you explain this answer?

    Lavanya Menon answered
    Change in position (X),
    P= momentum,
    P=mv.
    X ×P = h/4π.
    X× m v = h/4π.
    X= h/4πmv.
    X=6.625×10-34/4 ×3.14×9.1×10^-31×300.
    X=6.625×10-5/342.8.
    X=0.0192×10^-5.
    X= 19.2× 10-7.
    in question it is given to take accurate up to 0.001%.= 1×10-3/100=1 ×10-5.
    X= 19.2 ×10-7/10-5.
    X=19.2 × 10-2.

    The number of radial nodes for 3p orbital is __________.
    • a)
      3
    • b)
      4
    • c)
      2
    • d)
      1
    Correct answer is option 'D'. Can you explain this answer?

    Swara Saha answered
    Number of radial nodes = n-1 – 1
    For 3p orbital, n = 3 – 1 – 1 = 1
    Number of radial nodes = 3 – 1 – 1 = 1. 

    In the relationship ∆x. ∆p =   , ∆p is:
    • a)
      Certainty in momentum
    • b)
      Certainty in position
    • c)
      Uncertainty in momentum
    • d)
      Uncertainty in position
    Correct answer is option 'C'. Can you explain this answer?

    Hansa Sharma answered
    The uncertainty principle is alternatively expressed in terms of a particle’s momentum and position. The momentum of a particle is equal to the product of its mass times its velocity. Thus, the product of the uncertainties in the momentum and the position of a particle equals h/(4π) 

     Which of the following subatomic particles is responsible for the spectrum of radiation emitted by an element or compound?
    • a)
      neutron
    • b)
      electron
    • c)
      proton
    • d)
      photon
    Correct answer is option 'B'. Can you explain this answer?

    Om Desai answered
    Any radiation is emitted in the quantized form as photons. These photons are actually generated when an electron changes its energy level. This can happen if the atom gets the required work function. For e.g. The emission of X Ray. When the cathode ray hits the nuclei of heavier metals, two cases may occur - 
    1)Nuclei absorbs the electron from K shell and this process results in radiation of energy in form of X Ray photons. 
    2)Auger Effect: Sometimes during the collision, an electron from main atom can also be emitted, releasing energy in form of X Ray photons. So, Now it should be more clear that while photons are the product, the real culprit behind the crime scene. So correct option is B These things can be understood easily if you know the basics of Particle Physics.

     The charge on electron was determined by
    • a)
      Crooks
    • b)
      Bohr
    • c)
      Milliken
    • d)
      Schrodinger
    Correct answer is option 'C'. Can you explain this answer?

    Naina Bansal answered
    Millikan
    The experiment helped earn Millikan a Nobel prize in 1923 but has been a source of some controversy over the years. J. J. Thomson discovered the electron in 1897 when he measured the charge-to-mass ratio for electrons in a beam. But the value of the charge and whether it was fundamental remained open questions.

    Chapter doubts & questions for Structure of Atom - NCERT Based Tests for NEET 2025 is part of NEET exam preparation. The chapters have been prepared according to the NEET exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for NEET 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.

    Chapter doubts & questions of Structure of Atom - NCERT Based Tests for NEET in English & Hindi are available as part of NEET exam. Download more important topics, notes, lectures and mock test series for NEET Exam by signing up for free.

    Top Courses NEET

    Related NEET Content