| 1. | \(1.5\times 10^{17}\) | 2. | \(3\times 10^{19}\) |
| 3. | \(1.5\times 10^{25}\) | 4. | \(3\times 10^{25}\) |
| 1. | \(\dfrac{(Z - 13)}{\left(A - Z - 23\right)}\) | 2. | \(\dfrac{\left(Z - 18\right)}{\left(A - 36\right)}\) |
| 3. | \(\dfrac{\left(Z - 13\right)}{\left(A - 36\right)}\) | 4. | \(\dfrac{\left(Z - 13\right)}{\left(A - Z - 13\right)}\) |
An element \(\mathrm{X}\) decays, first by positron emission, and then two \(\alpha\text-\)particles are emitted in successive radioactive decay. If the product nuclei have a mass number \(229\) and atomic number \(89\), the mass number and the atomic number of element \(\mathrm{X}\) are:
1. \(237,~93\)
2. \(237,~94\)
3. \(221,~84\)
4. \(237,~92\)
| 1. | It may emit \(\alpha\text-\)particle. |
| 2. | It may emit \(\beta^{+}\) particle. |
| 3. | It may go for \(K\) capture. |
| 4. | All of the above are possible. |
Two nuclei have their mass numbers in the ratio of \(1:3.\) The ratio of their nuclear densities would be:
1. \(1:3\)
2. \(3:1\)
3. \((3)^{1/3}:1\)
4. \(1:1\)
The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an:
| 1. | isobar of a parent. | 2. | isomer of a parent. |
| 3. | isotone of a parent. | 4. | isotope of a parent. |
A nucleus \({ }_{{n}}^{{m}} \mathrm{X}\) emits one \(\alpha\text -\text{particle}\) and two \(\beta\text- \text{particle}\) The resulting nucleus is:
| 1. | \(^{m-}{}_n^6 \mathrm{Z} \) | 2. | \(^{m-}{}_{n}^{4} \mathrm{X} \) |
| 3. | \(^{m-4}_{n-2} \mathrm{Y}\) | 4. | \(^{m-6}_{n-4} \mathrm{Z} \) |
Consider the following statements:
| (I) | All isotopes of elements have the same number of neutrons. |
| (II) | Only one isotope of an element can be stable and non-radioactive. |
| (III) | All elements have isotopes. |
| (IV) | All isotopes of carbon can form chemical compounds with oxygen\(\text-16\). |
The correct option regarding an isotope is:
| 1. | (III) and (IV) only |
| 2. | (II), (III), and (IV) only |
| 3. | (I), (II), and (III) only |
| 4. | (I), (III), and (IV) only |