1. | \(\dfrac{1}{4}\) | 2. | \(\dfrac{4}{9}\) |
3. | \(\dfrac{9}{4}\) | 4. | \(4\) |
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 |
1. | total energy of electron in \(1\text{st}\) orbit of \(\mathrm{He}^{+}\) |
2. | total energy of electron in \(3\text{rd}\) orbit of \(\mathrm{He}^{+}\) |
3. | total energy of electron in \(2\text{nd}\) orbit of \(\mathrm{Li}^{++}\) |
4. | total energy of electron in \(3\text{rd}\) 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 \(66.0 ~\text{eV}\).
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 \(\mathrm{H}\text-\)atom to the speed of light?
1. | \(\dfrac{1}{137}\) | 2. | \(137\) |
3. | \(\dfrac{1}{83}\) | 4. | \(\dfrac{1}{47}\) |