# The de Broglie wavelength of electron of He+ ion is 3.329Å. If the photon emitted upon de-excitation of this He+ ion is made to hit H atom in its ground state so as to liberate electron from it, what will be the de Broglie's wavelength of photoelectron ? 1. 0.1518 Å 2. 6.1518 Å 3. 2.3518 Å 4. 4.1218 Å

Subtopic:  De Broglie Equation |
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Velocity of helium atom at 300 K is 2.40 x 102 meter per sec. What is its wavelength? (mass number of helium is 4) -

1. 0.416 nm

2. 0.83 nm

3. 803 Å

4. 8000 Å

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The de-Broglie wavelength of a particle having the momentum of
3.3 x 10-24 kg m s-1 will be;

1. 0.002 Å

2. 0.02 Å

3. 0.2 Å

4. 2Å

Subtopic:  Planck's Theory |
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Which of the following statements is not true with respect to photoelectric effect -

1. The plot of kinetic energy of the photoelectrons against frequency of absorbed radiation gives a straight line parallel to x-axis

2. The plot of K.E. of the photoelectrons against frequency of absorbed radiation gives a straight line with slope equal to h and intercept to work function of metal

3. The plot of kinetic energy of the photoelectrons versus the intensity of incident radiation with constant frequency gives a straight line parallel to x-axis

4. When intensity of light is increased the number of photons ejected increases but the energies of these electrons are the same.

Subtopic:  Photo Electric Effect |
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The first line in the Lyman series in the spectrum of hydrogen atom occurs at a wavelength of 1215 Å and the limit for Balmer series is 3645 Å. Calculate the wavelength corresponding to series limit of Lyman series.

1. 911.2 Å

2. 812.2 Å

3. 712.2 Å

4. 678.4 Å

Subtopic:  Hydrogen Spectra |
62%
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The correct order of increasing energy of atomic orbital is:

1. 3s, 3p, 4s, 3d, 4p

2. 3s, 3p, 3d, 4s, 4p

3. 3s, 3p, 4s, 4p, 3d

4. 3s, 3p, 3d, 4p, 4s

Subtopic:  AUFBAU Principle |
80%
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In Rutherford's alpha scattering experiment using gold foil, the kinetic energy of the alpha particle was 1.2 x 10-12J. For a head on collision, using the formula K.E. = $\frac{1}{4{\mathrm{\pi \epsilon }}_{0}}$x 2Ze2/r0 , what may be the magnitude of r0 [ The nuclear radius of gold, Z=79; $\frac{1}{4{\mathrm{\pi \epsilon }}_{0}}$= 9 x 109 new-ton/meter2 coulomb-2, e= 1.6x10-19 coulomb]

1. 3 x 10-14m

2. 1.3 x 10-14m

3. 2.1 x 10-14m

4. 4.3 x 10-14m

Subtopic:  Introduction of Atomic Structure |
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The quantum number of the most energetic electron in an Ne atom in the first excited state is

 1 2, 1, 0, +1/2 2 3, 1, 1, +1/2 3 3, 0, 0, +1/2 4 3, 1, 0, +1/2
Subtopic:  Quantum Numbers & Schrodinger Wave Equation |
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The frequency of line spectrum of sodium is 5.09 x 1014 sec-1. Its wavelength (in nm) will be -[C= 3x108m/sec]

1. 510nm

2. 420nm

3. 589nm

4. 622nm

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The total number of neutrons in dipositive zinc ions with mass number 70 is -

1. 34

2. 40

3. 36

4. 38

Subtopic:  Number of Electron, Proton & Neutron |
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