Structure of Atom Part 1: Bohr's ModelContact Number: 8527521718Structure of Atom Part 1: Bohr's ModelContact Number: 8527521718Bohr's atomic model provides explanations for:
| 1. | The spectrum of hydrogen atoms only.
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| 2. | The spectrum of an atom or ion containing only one electron.
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| 3. | The spectrum of hydrogen molecule.
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| 4. | The solar spectrum. |
The electronic transition in the hydrogen atom that emits maximum energy is:
1. 2 1
2. 1 4
3. 4 3
4. 3 2
An element with atomic mass Z consists of two isotopes of mass number Z-1 and Z + 2. The percentage abundance of the heavier isotope is -
1. 0.25
2. 33.3
3. 66.6
4. 75
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
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
Which of the following has greater number of electrons than neutrons?
1. Al3+
2. O2-
3. F-
4. C
The maximum wavelength in the Lyman series of He+ ion is-
1. 3R
2. 1/3R
3. 1/R
4. 2R
When an electron jumps from n=5 to n=1 in a hydrogen atom, the number of spectral lines obtained is
| 1. | 3 | 2. | 4 |
| 3. | 6 | 4. | 10 |
Isodiaphers among the following options is :
1. and
2. and
3. and
4. and
The incorrect statement regarding the characteristics of X-rays is :
1. The radiation can ionize the gas
2. It causes a fluorescence effect on ZnS
3. It is deflected by electric and magnetic fields
4. Have a shorter wavelength than ultraviolet rays
In photoelectric effect, the kinetic energy of photoelectrons increases linearly with the:
1. Wavelength of incident light
2. Frequency of incident light
3. Velocity of incident light
4. Atomic mass of an element
The largest de Broglie wavelength among the following (all have equal velocity) is:
1. molecule
2. molecule
3. Electron
4. Proton
Of the following transitions in hydrogen atom, the one which gives an absorption line of lowest frequency is:
1. n = 1 to n = 2
2. n = 3 to n = 8
3. n = 2 to n = 1
4. n = 8 to n = 3
The number of protons, neutrons and electrons in \( _{71}^{175}Lu\) respectively, are:
1. 104, 71 and 71
2. 71, 71 and 104
3. 175, 104 and 71
4. 71, 104 and 71
The energy of an electron in the first Bohr's orbit of an H-atom is -13.6 eV. The possible energy value (s) of the excited state(s) for electrons in Bohr's orbits of hydrogen is (are):
1. -3.4 eV
2. -4.2 eV
3. -6.8 eV
4. +6.8 eV
The wavelength of the radiation emitted when in a H atom, the electron falls from infinity to stationary state (n=1), is:
1.
2. 192 nm
3. 406 nm
4. 91 nm
The concept that contradicts the Bohr Model of an atom is:
| 1. | Rutherford Model | 2. | Heisenberg's Uncertainty Principle |
| 3. | J.J. Thomson Model | 4. | Photoelectric Effect |
Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. The work function (W0) of the metal is:
1. 3.109 × 10–20 J
2. 2.922 × 10–19 J
3. 4.031 × 1019 J
4. 2.319 × 10–18 J
The ratio of the wavelengths of the last lines of the Balmer to Lyman series is
| 1. | 4:1 | 2. | 27:5 |
| 3. | 3:1 | 4. | 9:4 |
For a subatomic particle, the uncertainty in position is same as that of uncertainty in its momentum. The
least uncertainty in its velocity can be given as
1.
2.
3.
4.