Nuclear Physics & Ionizing Radiation

Answers

Unit 47: Alpha & Beta Decay

Q47.1) a) 2 protons, 2 neutrons

b) 6 protons, 8 neutrons

c) 92 protons, 146 neutrons

d) 90 protons, 140 neutrons

Q47.2) a) a negative beta particle and an anti-neutrino

b) ²³⁴Th

c)¹⁰C

Q47.3) It will undergo positive beta decay into a positive beta particle, a neutrino, and an atom of ¹⁴N.

Unit 48: Binding Energy

Q48.1) 39.3 MeV

Q48.2) 5.61 MeV

Q48.3) Iron is the most stable nucleus because it has the highest average binding energy per nucleon of any nucleus in existence (energy is never released in the fusion or fission of iron). Fusing multiple nuclei together into one with a higher average binding energy per nucleon always releases energy, so fusing two deuterium atoms intoo one helium atom releases energy (nuclear fusion). Conversely, breaking apart a nucleus into substituents with higher average binding energy per nucleon also releases energy, so the fission a ²³⁶U also releases energy.

Unit 49: Exponential Decay & Half-Life

Q49.1) 5.77 x 10⁻⁴ yr⁻¹

Q49.2) 1.2 min⁻¹

Q49.3) 1.05 x 10¹⁰ years

Q49.4) 4631 years

Q49.5) 4 days

Q50.1) a) 2.86 cm

b) 1.98 cm

Q50.2) 8.31 cm

Q50.3) 83.5%

Unit 50: Linear Attenuation

Unit 51: Radiation Dose

Q51.1) 2 Gy

Q51.2) 20 Sv

Q51.3) B < C < A