The de-Broglie relation used to obtain the time-independent Schrödinger equation employs λ = h / √{2m(E - U)}, matching option A per the block's answer hint.

Iodine-131 is commonly used in the treatment of thyroid conditions, including thyroid cancer.

Fermi energy for a Fermi gas scales as density^{2/3}, so option (b) is correct.

Beta-minus emission converts a neutron to a proton, reducing the neutron-to-proton ratio, so it decreases.

Alkali metals like sodium generally have lower work functions compared to Al, Si, or carbon.

Uranium and plutonium contain fissile isotopes commonly used in fission, so option C is correct.

Electron volt (eV) is the standard convenient unit for energies of sub-atomic particles.

The OCR-provided answer hint for this block indicates option A; the Bohr radius (first orbit radius) is commonly listed as 0.529 Å.

Mass rate = 1×10^-6 kg/s gives power = m c^2 ≈ 1×10^-6 × 9×10^16 = 9×10^10 W = 9×10^7 kW.

The OCR answer key indicates 'Electrostatic one'; muons interact electromagnetically with matter (electrostatic/electromagnetic interactions).