Match the LIST-I with LIST-II

LIST-I	LIST-II
A. ¹n + ²³⁵₉₂U arrow ¹⁴⁰₅₄Xe + ⁹⁴₃₈Sr + 2¹₀n${}^1\mathrm{n} + {}^{235}_{92}\mathrm{U} \rightarrow {}^{140}_{54}\mathrm{Xe} + {}^{94}_{38}\mathrm{Sr} + 2{}^1_0\mathrm{n}$	I. Chemical reaction
B. 2H₂ + O₂ arrow 2H₂O$2\mathrm{H}_2 + \mathrm{O}_2 \rightarrow 2\mathrm{H}_2\mathrm{O}$	II. Fusion with +ve$+\mathrm{ve}$ Q value
C. ²₁H + ²₁H arrow ³He + ¹₀n${}^2_1\mathrm{H} + {}^2_1\mathrm{H} \rightarrow {}^3\mathrm{He} + {}^1_0\mathrm{n}$	III. Fission
D. ¹₁H + ³₁H arrow ²₁H + ²₁H${}^1_1\mathrm{H} + {}^3_1\mathrm{H} \rightarrow {}^2_1\mathrm{H} + {}^2_1\mathrm{H}$	IV. Fusion with -ve$-\mathrm{ve}$ Q value

Choose the correct answer from the options given below:

Related Formula

• Nuclear Fission: Heavy nucleus splits into intermediate lighter fragments after absorbing a neutron.
• Nuclear Fusion: Extremely light isotopes combine to form heavier nuclei.
• Q-value: Positive for exothermic nuclear processes (releasing energy) and negative for endothermic nuclear processes (absorbing energy).

Core Logic

Let us check each reaction:

• Reaction A: ¹n + ²³⁵₉₂U arrow ¹⁴⁰₅₄Xe + ⁹⁴₃₈Sr + 2¹₀n${}^1\mathrm{n} + {}^{235}_{92}\mathrm{U} \rightarrow {}^{140}_{54}\mathrm{Xe} + {}^{94}_{38}\mathrm{Sr} + 2{}^1_0\mathrm{n}$

This is a heavy Uranium nucleus absorbing a neutron and splitting into smaller fragments. This is the definition of Nuclear Fission (III).

• Reaction B: 2H₂ + O₂ arrow 2H₂O$2\mathrm{H}_2 + \mathrm{O}_2 \rightarrow 2\mathrm{H}_2\mathrm{O}$

This represents the combination of hydrogen and oxygen molecules to form water, which is a classic exothermic Chemical reaction (I).

• Reaction C: ²₁H + ²₁H arrow ³He + ¹₀n${}^2_1\mathrm{H} + {}^2_1\mathrm{H} \rightarrow {}^3\mathrm{He} + {}^1_0\mathrm{n}$

Light Deuterium nuclei fuse together to form Helium-3, releasing considerable energy (Q > 0$Q > 0$). This is Fusion with positive Q value (II).

• Reaction D: ¹₁H + ³₁H arrow ²₁H + ²₁H${}^1_1\mathrm{H} + {}^3_1\mathrm{H} \rightarrow {}^2_1\mathrm{H} + {}^2_1\mathrm{H}$

Proton and Tritium reacting to form Deuteron products. Since this reaction has products with a lower binding energy than the reactants, it is an endothermic process. Hence, it is Fusion with negative Q value (IV).

Step 1: Alignment

Let's summarize the matches:

• A arrow$\rightarrow$ III
• B arrow$\rightarrow$ I
• C arrow$\rightarrow$ II
• D arrow$\rightarrow$ IV

This perfectly corresponds to Option (2).

Pattern Recognition

Identifying chemical vs. nuclear reactions is trivial (chemical reactions involve molecular change like 2H₂ + O₂$2\mathrm{H}_2 + \mathrm{O}_2$, whereas nuclear reactions involve changes in nuclear isotopes). Always use chemical reactions to instantly lock in a match (B-I) and narrow down options!

Chapter Mix

Class 12 Physics: Nuclei Class 11 Chemistry: Chemical Bonding and Molecular Structure