Physics & Pharmacy · Interactive
Physics Playground
Build intuition for the two calculations trainees meet most — how activity decays, and how a ⁹⁹Mo/⁹⁹ᵐTc generator rebuilds between elutions. Drag the sliders; everything updates live.
Radioactive decay
A(t) = A₀·e^(−λt), λ = ln2 / T½
370Remaining (MBq)
50.0%% remaining
1.00Half-lives
⁹⁹Mo/⁹⁹ᵐTc generator elution
Daughter build-up after elution (transient equilibrium)
100%⁹⁹ᵐTc (% of peak)
≈23 hTime to maximum
0.957A(Tc)/A(Mo) at eq.
Activity converter
Megabecquerel ⇄ millicurie · 1 mCi = 37 MBq (exact)
⇄
740 MBq = 20.00 mCi
Typical adult reference activities — illustrative; confirm against EANM/SNMMI & local protocol
⁹⁹ᵐTc-MDP bone740 MBq · 20 mCi
¹⁸F-FDG PET370 MBq · 10 mCi
⁹⁹ᵐTc-MAG3 renal100 MBq · 2.7 mCi
⁶⁸Ga-DOTATATE150 MBq · 4.1 mCi
Standard physical constants (⁹⁹Mo T½ 66 h, ⁹⁹ᵐTc T½ 6.01 h, 87.5% branching to the metastable state). Educational — for intuition, not dosimetry.