From the statements given below:
(A) The angular momentum of an electron in the $n^{th}$ orbit is an integral multiple of $h$.
(B) Nuclear forces do not obey the inverse square law.
(C) Nuclear forces are spin dependent.
(D) Nuclear forces are central and charge independent.
(E) Stability of a nucleus is inversely proportional to the value of the packing fraction.
Choose the correct answer from the options given below:
Answer: (C) (A), (B), (C), (E) only
- (A) Bohr's postulate: $L = n\dfrac{h}{2\pi}$, an integral multiple of the reduced Planck constant ($h/2\pi$). This is the statement intended.
- (B) True: nuclear forces are short range and fall off much faster than $1/r^2$.
- (C) True: nuclear forces depend on the relative spin orientation of the nucleons.
- (D) False: nuclear forces are charge independent but **non-central**.
- (E) True: a smaller packing fraction means a more stable nucleus.
Only statement (D) is wrong, so the answer is (A), (B), (C), (E).
Solution by Sreeraj P, M.Sc Physics