Inner shell electronic transitions in atoms produce characteristic X-rays specific to the element.

Bohr's quantization postulate states the angular momentum is an integral multiple of h/2π.

Solid state detectors typically provide high efficiency and resolution for radiation detection compared to the others listed.

Typical reactor turbine steam temperatures are around 300°C rather than the much higher values shown in options A and B.

The Rydberg constant R∞ has value approximately 1.0974 × 10^7 m^-1, corresponding to option B.

The block header provides answer hint 'A', so option A is chosen as the effective-range relation per the OCR answer key.

The melting point is the temperature at which the crystal lattice breaks down and the solid becomes liquid.

The symbol λ denotes the decay constant of a radioactive nuclide.

The whole number rule is associated with Prout's hypothesis which proposed whole-number atomic weights.

Annihilation (matter converting to photons) is the reverse process of pair production.