The plot of binding energy per nucleon against the mass number for stable nuclei is shown in the figure. Which curve is correct?

If $M_{O}$ is the mass of an oxygen isotope ${ }_{8}^{17}O$, $M_{p}$ and $M_{n}$ are the masses of a proton and a neutron, respectively, the nuclear binding energy of the isotope is

If mass-energy equivalence is taken into account,when water is cooled to form ice,the mass of water should

The sun radiates energy in all directions. The average radiation received on the earth's surface from the sun is $1.4 \; kW/m^2$. The average earth-sun distance is $1.5 \times 10^{11} \; m$. Calculate the mass lost by the sun per day $(1 \; \text{day} = 86400 \; s)$.

The mass of a $H$-atom is less than the sum of the masses of a proton and an electron. Why is this?

An electron and a positron annihilate each other to produce two $\gamma$-ray photons of equal energy. The minimum energy of each photon is .....