From simple symmetry and energy considerations it can be concluded that ${}^{98}\mathrm{Tc}$ might undergo electron capture decay (EC). In this work we provide evidence for an EC decay of ${}^{98}\mathrm{Tc}$ measuring 2.67 g $\mathrm{K}\left[\mathrm{Tc}{\mathrm{O}}_4\right]$ that contains approximately 1 GBq of ${}^{99}\mathrm{Tc}$. By use of a lead shielding for the sample, it was possible to identify the coincident $4+\to 2+$ and $2+\to 0+\gamma$ transitions in the daughter nuclide ${}^{98}\mathrm{Mo}$ at the University of Cologne's Cologne Clover Counting setup of the Institute for Nuclear Physics. For the first time, the EC/${\beta }^{-}$ branching ratio of 0.29(3)% was determined directly. With a $logft$ of 14.21(7) this decay does almost tie with the $logft$ of the ${}^{36}\mathrm{Cl}$ EC decay [14.23(1)] for the same highest second forbidden nonunique transition.

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• Beta decay
• Electromagnetic transitions
• Electron & muon capture
• Nuclear decay
• Nuclear transition rates