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-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

When ${}_{3}L{i}^7$ nuclei are bombarded by protons, and the resultant nuclei are ${}_{4}B{e}^8$, the emitted particles will be:

What is the respective number of $\alpha$ and $\beta$-particles emitted in the following radioactive decay?
\(X^{200}_{90}\rightarrow Y^{168}_{80}\)

If a proton and anti-proton come close to each other and annihilate, how much energy will be released?

Fusion reaction takes place at a higher temperature because:

Which of the following pairs of nuclei are isotones?

1. ${}_{34}{}^{74}\mathrm{Se},$ ${}_{31}{}^{71}\mathrm{Ca}$          

2. ${}_{42}{}^{92}\mathrm{Mo},$ ${}_{40}{}^{92}\mathrm{Zr}$

3. ${}_{38}{}^{81}\mathrm{Sr},$ ${}_{38}{}^{86}\mathrm{Sr}$             

4. ${}_{20}{}^{40}\mathrm{Ca},$ ${}_{16}{}^{32}\mathrm{S}$

Determine the energy released in the process:

${}_{1}H_2+{}_{1}H_2\to {}_{2}H{e}^4+Q$

Given: M $\left({}_{1}H_2\right)$= 2.01471 amu

            M$\left({}_{2}H{e}^4\right)$= 4.00388 amu

1. 3.79 MeV
2.13.79 MeV
3. 0.79 MeV 
4. 23.79 MeV

Two nuclei fuse together to form a single nucleus as ${}_1{}^2\mathrm{A}+{}_1{}^2\mathrm{A}\to$ ${}_2{}^4\mathrm{B}$. If binding energy per nucleon of A and B are respectively x and y, then the energy released in the process is:

If $\frac{N}{Z}$ ratio in a nucleus is smaller than the required value for stability, then: