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 \(\mathrm{Li}^{++}\) |
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
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
The difference between nth and (n+1)th Bohr's radius of the 'H' atom is equal to its (n - 1)th Bohr's radius. What is the value of n?
1. 1
2. 2
3. 3
4. 4
What is the ratio of the energies of the hydrogen atom in its first and second excited states?
1.
2.
3.
4. 4
Which of the following transitions gives a photon the maximum energy?
1. n = 1 to n = 2
2. n = 2 to n = 1
3. n = 2 to n = 6
4. n = 6 to n = 2
Whose atomic model describes electrons being embedded in a gel of positive charge?
1. | Dalton's model |
2. | Bohr's model |
3. | Thomson's model |
4. | Rutherford's model |
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
The ratio of the total acceleration of the electron in a singly ionised helium atom and a hydrogen atom (both in the ground state) is:
1. 1
2. 8
3. 4
4. 16