## Master Isotope Table — NIST SRD-128 Kα₁ (Z = 41–60)
| Z | Elem | Known | Stable | Unstable | Pred. | Gap | Nuclear γ (keV) | NIST Kα₁ (keV) | Context |
|---:|:---:|---:|---:|---:|---:|---:|---:|---:|---|
| 41 | Nb | 34 | 1 | 33 | 81 | 47 | 765.8 | 16.615 | ⁹⁵Nb fission product |
| 42 | Mo | 35 | 7 | 28 | 83 | 48 | 181.1 | 17.479 | ⁹⁹Mo → ⁹⁹ᵐTc medical parent |
| 43 | Tc | 36 | 0 | 36 | 85 | 49 | 140.5 | 18.367 | ⁹⁹ᵐTc SPECT γ |
| 44 | Ru | 37 | 7 | 30 | 88 | 51 | 497.1 | 19.279 | ¹⁰³Ru fallout tracer |
| 45 | Rh | 35 | 1 | 34 | 83 | 48 | — | 20.216 | stable; XRF calibration |
| 46 | Pd | 36 | 6 | 30 | 85 | 49 | — | 21.176 | stable; XRF calibration |
| 47 | Ag | 38 | 2 | 36 | 90 | 52 | 657.8 | 22.163 | ¹¹⁰ᵐAg tracer |
| 48 | Cd | 39 | 8 | 31 | 93 | 54 | 88.0 | 23.173 | ¹⁰⁹Cd calibration |
| 49 | In | 39 | 2 | 37 | 93 | 54 | 171.3 / 245.4 | 24.209 | ¹¹¹In imaging |
| 50 | Sn | 40 | 10 | 30 | 95 | 55 | 391.7 | 25.271 | ¹¹³Sn tracer |
| 51 | Sb | 36 | 2 | 34 | 85 | 49 | 602.7 / 1691 | 26.359 | ¹²⁴Sb activation |
| 52 | Te | 38 | 8 | 30 | 90 | 52 | 159.0 | 27.472 | ¹²³ᵐTe γ emitter |
| 53 | I | 37 | 1 | 36 | 88 | 51 | 364.5 | 28.612 | ¹³¹I medical |
| 54 | Xe | 40 | 9 | 31 | 95 | 55 | 81.0 | 29.779 | ¹³³Xe tracer |
| 55 | Cs | 39 | 1 | 38 | 93 | 54 | 661.7 | 30.973 | ¹³⁷Cs fallout |
| 56 | Ba | 40 | 7 | 33 | 95 | 55 | 356.0 | 32.193 | ¹³³Ba calibration |
| 57 | La | 39 | 1 | 38 | 93 | 54 | 1596.5 | 33.442 | ¹⁴⁰La fission prod. |
| 58 | Ce | 40 | 4 | 36 | 95 | 55 | 145.4 | 34.717 | ¹⁴¹Ce tracer |
| 59 | Pr | 39 | 1 | 38 | 93 | 54 | — | 36.019 | stable; XRF line |
| 60 | Nd | 41 | 5 | 36 | 97 | 56 | 531.0 | 37.349 | ¹⁴⁷Nd tracer |
✅ That covers Z = 41–60.
Do you want me to continue with Z = 61–80 next?