If an alpha nucleus of energy bombards a heavy nuclear target of charge Ze, then the distance of closest approach for the alpha nucleus will be proportional to:
1. | \(\frac{1}{Ze} \) | 2. | \(v^2 \) |
3. | \(\frac{1}{m} \) | 4. | \(\frac{1}{v^4}\) |
The ratio of the longest wavelengths corresponding to the Lyman and Balmer series in the hydrogen spectrum is:
1. | \(\frac{3}{23}\) | 2. | \(\frac{7}{29}\) |
3. | \(\frac{9}{31}\) | 4. | \(\frac{5}{27}\) |
Given that the value of the Rydberg constant is \(10^{7}~\text{m}^{-1}\), what will be the wave number of the last line of the Balmer series in the hydrogen spectrum?
1. \(0.5 \times 10^{7}~\text{m}^{-1}\)
2. \(0.25 \times 10^{7} ~\text{m}^{-1}\)
3. \(2.5 \times 10^{7}~\text{m}^{-1}\)
4. \(0.025 \times 10^{4} ~\text{m}^{-1}\)
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
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
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 \(\mathrm{Li}^{++}\) |
The electric potential between a proton and an electron is given by where is a constant. Assuming Bohr’s model to be applicable, the variation of with n, n being the principal quantum number, is:
1.
2.
3.
4.
In a hypothetical Bohr hydrogen, the mass of the electron is doubled.
What will be the energy E0 and the radius r0 of the first orbit?
( is the Bohr radius)
1. | \(\mathrm{E}_0=-27.2 \mathrm{eV} ; \mathrm{r}_0=\mathrm{a}_0 / 2\) |
2. | \(\mathrm{E}_0=-27.2 \mathrm{eV} ; \mathrm{r}_0=\mathrm{a}_0\) |
3. | \(\mathrm{E}_0=-13.6 \mathrm{eV} ; \mathrm{r}_0=\mathrm{a}_0 / 2\) |
4. | \(\mathrm{E}_0=-13.6 \mathrm{eV} ; \mathrm{r}_0=\mathrm{a}_0\) |
What is the ratio of the longest to shortest wavelengths in Brackett series of hydrogen spectra?
1.
2.
3.
4.
What is the ratio of the largest to shortest wavelengths in the Lyman series of hydrogen spectra?
1.
2.
3.
4.