What was the fissionable material used in the bomb dropped at Nagasaki (Japan) in the year $1945$?

The energy released in the fusion of $2 \ kg$ of hydrogen deep in the sun is $E_{H}$ and the energy released in the fission of $2 \ kg$ of ${ }^{235} U$ is $E_U$. The ratio $\frac{E_H}{E_U}$ is approximately :
(Consider the fusion reaction as $4{ }_1^1 H + 2 e^{-} \rightarrow { }_2^4 He + 2 \nu + 6 \gamma + 26.7 \ MeV$,energy released in the fission reaction of ${ }^{235} U$ is $200 \ MeV$ per fission nucleus and $N_{A} = 6.023 \times 10^{23}$ )

$A$ nuclear fission process is given by $A^{240} \rightarrow B^{100} + C^{140} + Q$ (energy). If the binding energy per nucleon for nuclei $A, B,$ and $C$ are $7.6 \, MeV, 8.1 \, MeV,$ and $8.1 \, MeV$ respectively,then the energy $Q$ released is approximately $...... \, MeV$.

On fission,a $U^{235}$ nucleus releases $3 \times 10^{-11} \, J$ of energy. In a $1 \, GW$ nuclear reactor,$4.2 \%$ of this energy is converted to useful energy. The $U^{235}$ consumed (in grams) in half an hour is closest to (Avogadro number $N_A = 6.023 \times 10^{23}$)

If $200 \text{ MeV}$ of energy is released in the fission of one nucleus of ${ }_{92}^{236} U$,the number of nuclei that must undergo fission to release an energy of $1000 \text{ J}$ is

The nuclear fusion reaction is given as $_1H^2 + _1H^2 \to _2He^3 + n + 3.2 \, MeV$. How much energy is released when $2 \, kg$ of deuterium undergoes fusion?