The mass ratio of photons corresponding to the first lines of the Lymann and the Balmer series of the atomic spectrum of hydrogen is :

1. 5 : 27 2. 1 : 4
3. 27 : 5 4. 4 : 1

Subtopic:  Hydrogen Spectra |
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An electron, practically at rest, is initially accelerated through a potential difference of 100 volts. It then has a de Broglie wavelength=λ1Å. It then get retarded through 19 volts and then it has wavelength λ2 Å. A further retardation through 32 volts changes the wavelength to λ3.

What is (λ3-λ2)/λ1?

1. 20/41

2. 10/63

3. 20/63

4. 10/41

Subtopic:  De Broglie Equation |
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Which of the following has the maximum number of  unpaired electons-

1. Mg2+

2. Ti3+

3. V3+

4. Fe2+

Subtopic:  Number of Electron, Proton & Neutron |
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There are three energy levels in an atom. How many spectral lines are possible in its emission spectra?

1. One

2. Two

3. Three

4. Four

Subtopic:  Type of Spectra |
 75%

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The azimuthal quantum number characterizes:

1. e/m ratio of electron
2. Spin of electron

3. Angular momentum of the electron

4. Magnetic momentum of the electron

Subtopic:  Quantum Numbers & Schrodinger Wave Equation |
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For the energy levels in an atom, which one of the following statements is correct -

1. There are seven principal electron energy levels

2. The second principal energy level can have two 'sub energy levels and contains a maximum of eight electrons

3. The energy level can have a maximum of 32 electrons

4. The 4s sub-energy level is at higher energy than the 3d sub-energy level

Subtopic:  Hydrogen Spectra |
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Arrange the following particles in increasing order of values of e/m ratio: Electron(e), proton(p), neutron(n) and α-particle(α)

1. n,p,e,α

2. n,α,p,e

3. n,p,α,e

4. e,p,n,α

Subtopic:  Introduction of Atomic Structure |
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The increasing order of energy of electromagnetic radiation can be represented as: 

1. microwave < infrared < visible < X-ray.
2. X-ray < visible < infrared < microwave.
3. microwave < infrared < visible < radio waves.
4. X-ray < infrared < visible < microwave.
Subtopic:  Electromagnetic Radiation |
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The wavelength of the photoelectric threshold of metal is 230 nm. Determine the K.E. of photoelectron ejected from the surface by UV radiation emitted from the second-longest wavelength transition (downward) of an electron in Lyman series of the atomic spectrum of hydrogen. (R=1.09677 x 107 m-1)

1. 1.074 x 10-18 J

2. 1.937 x 10-18J

3. 6.213 × 10-18 J

4. 7.123 x 10-10J

 

 

Subtopic:  Hydrogen Spectra |
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Beryllium's fourth electron will have the four quantum numbers :

                         n               l               m             s

1.                    1               0                0             1/2

2.                    1               1                1             1/2

3.                    2               0                0             -1/2

4.                    2               1                 0             +1/2

Subtopic:  Quantum Numbers & Schrodinger Wave Equation |
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