In Rutherford's alpha-particle scattering experiment, only a few alpha particles rebound back because

A. The size of gold nucleus is very small as compared to the size of gold atom.

B. Alpha particle and gold nucleus have equal charge.

C. The impact parameter is minimum for a few alpha particles.

D. A few alpha particles have very high kinetic energy.

E. Only a few alpha particles undergo head-on collision with the nuclei.

Choose the correct answer from the options given below :

Two nuclei of mass number 3 combine with another nucleus of mass number 4 to yield a nucleus of mass number 10. If the binding energy per nucleon for the mass numbers 3,4 and 10 are $5.6 \mathrm{MeV}, 7.4 \mathrm{MeV}$ and 6.1 MeV , respectively, then in the process, $\Delta \mathrm{Mc}^2=$ $\_\_\_\_$ MeV .

The binding energy per nucleon of $^{209}_{83}Bi$ is _______ MeV.

[Take $m(^{209}_{83}Bi) = 208.980388\ \text{u}$, $m_p = 1.007825\ \text{u}$, $m_n = 1.008665\ \text{u}$, $1\ \text{u} = 931\ \text{MeV}/c^2$]

Angular momentum of an electron in a hydrogen atom is $\frac{3h}{\pi}$, then the energy of the electron is _____ eV.