What is the ratio of the circumference of the first Bohr orbit for the electron in the hydrogen atom to the de-Broglie wavelength of electrons having the same velocity as the electron in the first Bohr orbit of the hydrogen atom?
1. 1:1
2. 1:2
3. 1:4
4. 2:1
The Rutherford -particle experiment shows that most of the -particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom?
1. | Atom is hollow. |
2. | The whole mass of the atom is concentrated in a small center called the nucleus. |
3. | Nucleus is positively charged. |
4. | All of the above |
A hydrogen atom is excited from the ground state to the state of principal quantum number 4. Then the number of spectral lines observed will be:
1. 3
2. 6
3. 5
4. 2
How much is the total energy of an electron in the first orbit of a hydrogen atom equal to?
1. | total energy of electron in 1st orbit of \(\mathrm{He}^{+}\) |
2. | total energy of electron in 3rd orbit of \(\mathrm{He}^{+}\) |
3. | total energy of electron in 2nd orbit of \(\mathrm{Li}^{++}\) |
4. | total energy of electron in 3rd orbit of \(\mathrm{Li}^{++}\) |
An electron revolves around a nucleus of charge Ze. In order to excite the electron from the state n=3 to n=4, the energy required is 66.0 eV. The value of Z will be:
1. 25
2. 10
3. 4
4. 5
What is the ratio of the speed of an electron in the first orbit of an H-atom to the speed of light?
1.
2. 137
3.
4.
In the diagram shown below, two atomic transitions are shown. If then the value of λ will be:
1. 2000
2. 4000
3. 4500
4. 9000
Let f1 be the maximum frequency of the Lyman series, f2 be the frequency of the first line of the Lyman series, and f3 be the frequency of the series limit of the Balmer series, then which of the following is correct?
1. - =
2. - =
3. + =
4. 2 = +
If the wavelength of the first line in the Balmer Series of the hydrogen spectrum is λ, then what is the wavelength of the second line in this series?
1.
2.
3.
4.
In an atom, if the transition from n = 4 to n = 3 gives ultraviolet radiation, then to obtain infrared radiation, the transition should be:
1. | 5 → 4 | 2. | 3 → 2 |
3. | 2 → 1 | 4. | 3 → 1 |