Deduce equations for the following nuclear reactions:

(i) Molybdenum-98 absorbs a neutron.

(ii) The isotope produced in (a) (i) decays into technetium-99m.

Molybdenum-99 has a half-life of 66 hours, while technetium-99m has a half-life of 6 hours. Outline why technetium-99m is made on-site.

Outline two reasons, other than its half-life, why technetium-99m is so useful in medical diagnosis.

Outline the nature of the radioactive waste that is generated by the use of technetium-99m in medical diagnosis.

i

${}_{42}^{98}\mathrm{M}\mathrm{o}$ + ${}_0^1\mathrm{n}$ → ${}_{42}^{99}\mathrm{M}\mathrm{o}$

Accept ⁹⁸Mo + ¹n/n → ⁹⁹Mo.

ii

${}_{42}^{99}\text{Mo}\to {}_{43}^{99\text{m}}\text{Tc}+{}_{-1}^0\beta$

Accept “ ${}_{-1}^{0}e$” for “ ${}_{-1}^0\beta$”.

Accept “ ${}^{99}Mo\to {}_{}^{99\text{m}}Tc+\beta$”.

Accept “ ${}_{-1}^{0}e/e^{-}/e$” for “$\beta$”.

Do not penalize “ ${}_{}^{99}Tc$” for “ ${}_{}^{99\text{m}}Tc$”.

molybdenum-99 can be easily transported «before it decays»/more stable
OR
«most of» technetium-99m will decay during transportation

Do not accept just “short half-life of Tc-99m”

emits gamma rays
OR
emissions escape from body
OR
emissions detected by gamma camera
OR
radiation dose is low

chemically reactive/versatile/transition metal bonds to a range of «biologically active» substances

Do not accept “short half-life of Tc-99m”.
Accept “energy of photons produced is «relatively» low” and “no high energy beta emission” for M1.
Accept “…has ability to form tracers” for “…bonds to a range of «biologically active» substances".

low-level «radioactive» waste/LLW
OR
small amounts of ionizing radiation for short time