Time dilation required for survival fraction 1/8 over 60 km gives γβ ≈ 44.5, yielding β ≈ 0.99975, so option (d).

Scattering of X-rays by loosely bound electrons (using a graphite target) is the Compton effect.

The OCR answer hint indicates option C (1.2 × 10-10 s) as the half-life value for the E" hyperon in the text.

Radium-226 has a half-life of about 1.62 × 10^3 years, so 1620 years is the correct choice.

Work function is commonly expressed in electronvolts (eV), the energy required to remove an electron from a material.

In the Bohr model the total energy E = -K, so K/E = -1.

A hydrogen ion (H+) is a proton with no electrons, so it consists of one proton only; option B is correct.

Neutrons penetrate dense materials like steel much more effectively than charged particles or γ-rays of typical energies.

The block's provided answer key indicates option A; the OCR text shows multiple energy ranges and the header marks option A as correct.

Time dilation is the relativistic effect where elapsed time between events differs between reference frames.