| (a) | Isotones differ in the number of neutrons. |
| (b) | Isobars contain the same number of neutrons but differ in the number of protons. |
| (c) | No isotope of hydrogen is radioactive. |
| (d) | The density of the nucleus is much greater than that of an atom. |
| 1. | (a), (b) and (c) | 2. | (b), (c) and (d) |
| 3. | (b) and (c) | 4. | All of the above |
| 1. | \(\mathrm{R}\) | 2. | \(\dfrac{1}{R}\) |
| 3. | \(\dfrac{1}{\sqrt{R}}\) | 4. | \(\sqrt{R}\) |
Which of the following statements are correct regarding orbits and orbitals?
| (a) | An orbit is a circular path where electrons revolve. |
| (b) | An orbital is a 3D space with maximum electron probability (up to 90%). |
| (c) | The maximum electrons in an orbit are 2n2. |
| (d) | Orbitals are always circular in shape. |
| (e) | Orbitals follow the wave nature of electrons and the uncertainty principle. |
Options:
| 1. | a, b, and c | 2. | b, c, and e |
| 3. | a, b,c and e | 4. | a, c, and d |
| Assertion (A): | The mass numbers of most of the elements are fractional. |
| Reason (R): | Mass numbers are obtained by comparing with the mass number of carbon taken as \(12.\) |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False |
| 4. | Both (A) and (R) are False. |
| 1. | No two electrons can be in two separate orbitals. |
| 2. | No two electrons can be present with similar spin in an orbital. |
| 3. | Two electrons can exist in d orbital. |
| 4. | None of the above. |
| Statement I: | The value of wave function, \(\Psi\) depends upon the coordinates of the electron in the atom. |
| Statement II: | The probability of finding an electron at a point within an atom is proportional to the orbital wave function. |
| 1. | Statement I is True but Statement II is False. |
| 2. | Statement I is False but Statement II is True. |
| 3. | Both Statement I and Statement II are True. |
| 4. | Both Statement I and Statement II are False. |
| List I (Frequency region) | List II (Uses) |
| A. Radiofrequency | I. Radar |
| B. Microwave | II. Broadcast |
| C. Infra-red region | III. Heating |
| A | B | C | |
| 1. | II | I | III |
| 2. | I | II | III |
| 3. | I | III | II |
| 4. | II | III | I |