Master Isotope Table — Known vs Predicted +

What’s included per element:

Knownisotopes (experimental)
Stable (strict)(IUPAC; ultra–long-lived counted as radioactive)
Unstable(= Known − Stable)
Predicted(scaled to Neufcourt et al., 2020; total bound ≈ 7,759)
Gap(Predicted − Known)
Representative nuclear γ(keV) — an operational line used in environmental/medical/industrial monitoring
LBNL Kα₁ (keV)— characteristic X-ray fluorescence line (universal atomic resonance; Z = 6–92)

Frequency conversion (if you want to display frequencies):
( f\,[\mathrm{Hz}] \approx E\,[\mathrm{keV}] \times 2.418\times 10^{17} )

Table (Z = 1–118)

Z	Elem	Known	Stable	Unstable	Pred.	Gap	Nuclear γ (keV)	LBNL Kα₁ (keV)	Context
1	H	7	2	5	17	10	—	—	β-only (³H)
2	He	9	2	7	21	12	—	—	noble gas
3	Li	11	2	9	26	15	—	—	no standard γ
4	Be	12	1	11	28	16	—	—	no standard γ
5	B	13	2	11	31	18	—	—	no standard γ
6	C	15	2	13	36	21	—	0.277	XRF Kα₁
7	N	16	2	14	38	22	—	0.392	XRF Kα₁
8	O	17	3	14	40	23	—	0.525	XRF Kα₁
9	F	18	1	17	43	25	—	0.677	XRF Kα₁
10	Ne	19	3	16	45	26	—	0.849	XRF Kα₁
11	Na	20	1	19	47	27	1274.5	1.041	²²Na PET/industrial; Kα₁ XRF
12	Mg	22	3	19	52	30	—	1.253	XRF Kα₁
13	Al	22	1	21	52	30	—	1.486	XRF Kα₁
14	Si	23	3	20	55	32	—	1.740	XRF Kα₁
15	P	23	1	22	55	32	—	2.013	XRF Kα₁
16	S	24	4	20	57	33	—	2.307	XRF Kα₁
17	Cl	24	2	22	57	33	—	2.622	XRF Kα₁
18	Ar	24	3	21	57	33	1293.6	2.957	⁴¹Ar activation gas + XRF
19	K	24	2	22	57	33	1460.8	3.312	⁴⁰K natural background + XRF
20	Ca	24	6	18	57	33	—	3.691	XRF Kα₁
21	Sc	25	1	24	59	34	889.3 / 1120.5	4.090	⁴⁶Sc (activation tracer) + XRF
22	Ti	26	5	21	62	36	1157.0	4.511	⁴⁴Ti (via ⁴⁴Sc γ) + XRF
23	V	26	1	25	62	36	983.5	4.952	⁴⁸V (PET/activation) + XRF
24	Cr	26	4	22	62	36	320.1	5.415	⁵¹Cr tracer + XRF
25	Mn	26	1	25	62	36	834.8	5.899	⁵⁴Mn industrial + XRF
26	Fe	28	4	24	66	38	—	6.404	Fe Kα₁ (ubiquitous XRF)
27	Co	29	1	28	69	40	1173.2 / 1332.5	6.930	⁶⁰Co γ pair + XRF
28	Ni	31	5	26	74	43	—	7.478	XRF Kα₁
29	Cu	29	2	27	69	40	—	8.048	Cu Kα₁ (calibration)
30	Zn	30	5	25	71	41	1115.5	8.638	⁶⁵Zn + XRF
31	Ga	31	2	29	74	43	93.3 / 184.6 / 300.2	9.251	⁶⁷Ga SPECT + XRF
32	Ge	32	5	27	76	44	—	9.886	XRF Kα₁
33	As	33	1	32	78	45	559.1 / 595.9	10.543	⁷⁴As + XRF
34	Se	30	6	24	71	41	136 / 265 / 279.5	11.222	⁷⁵Se + XRF
35	Br	31	2	29	74	43	554.3 / 776.5	11.924	⁸²Br tracer + XRF
36	Kr	32	6	26	76	44	514.0	12.648	⁸⁵Kr (noble gas) + XRF
37	Rb	32	1	31	76	44	511 (annih.)	13.395	⁸²Rb PET + XRF
38	Sr	34	4	30	81	47	514.0	14.165	⁸⁵Sr + XRF
39	Y	32	1	31	76	44	898.0 / 1836.0	14.958	⁸⁸Y calibration + XRF
40	Zr	34	5	29	81	47	724.2	15.775	⁹⁵Zr fission prod. + XRF
41	Nb	34	1	33	81	47	765.8	16.615	⁹⁵Nb fission prod. + XRF
42	Mo	35	7	28	83	48	181.1	17.479	⁹⁹Mo → ⁹⁹ᵐTc medical
43	Tc	36	0	36	85	49	140.5	18.367	⁹⁹ᵐTc SPECT
44	Ru	37	7	30	88	51	497.1	19.279	¹⁰³Ru fallout + XRF
45	Rh	35	1	34	83	48	—	20.216	Stable, XRF Kα₁
46	Pd	36	6	30	85	49	—	21.176	Stable, XRF Kα₁
47	Ag	38	2	36	90	52	657.8	22.163	¹¹⁰ᵐAg environmental tracer
48	Cd	39	8	31	93	54	88.0	23.173	¹⁰⁹Cd calibration source
49	In	39	2	37	93	54	171.3 / 245.4	24.209	¹¹¹In imaging + XRF
50	Sn	40	10	30	95	55	391.7	25.271	¹¹³Sn tracer + XRF
51	Sb	36	2	34	85	49	602.7 / 1691	26.359	¹²⁴Sb activation + XRF
52	Te	38	8	30	90	52	159.0	27.472	¹²³ᵐTe, ¹²⁵I precursors + XRF
53	I	37	1	36	88	51	364.5	28.612	¹³¹I medical tracer + XRF
54	Xe	40	9	31	95	55	81.0	29.779	¹³³Xe noble gas tracer
55	Cs	39	1	38	93	54	661.7	30.973	¹³⁷Cs fallout + XRF
56	Ba	40	7	33	95	55	356.0	32.193	¹³³Ba calibration + XRF
57	La	39	1	38	93	54	1596.5	33.442	¹⁴⁰La fission prod. + XRF
58	Ce	40	4	36	95	55	145.4	34.717	¹⁴¹Ce tracer + XRF
59	Pr	39	1	38	93	54	—	36.019	Stable; XRF Kα₁
60	Nd	41	5	36	97	56	531.0	37.349	¹⁴⁷Nd tracer + XRF
61	Pm	39	0	39	93	54	—	38.707	No stable isotopes; XRF Kα₁
62	Sm	41	7	34	97	56	333.0	40.093	¹⁵³Sm therapy + XRF
63	Eu	40	2	38	95	55	121.8 / 344.3	41.507	¹⁵²Eu calibration + XRF
64	Gd	41	7	34	97	56	103.2	42.950	¹⁵³Gd imaging agent + XRF
65	Tb	39	1	38	93	54	298.6	44.422	¹⁶⁰Tb therapy + XRF
66	Dy	40	7	33	95	55	—	45.924	Stable; XRF Kα₁
67	Ho	39	1	38	93	54	133.0	47.456	¹⁶⁶Ho therapy + XRF
68	Er	40	6	34	95	55	—	49.017	Stable; XRF Kα₁
69	Tm	39	1	38	93	54	88.0	50.609	¹⁷⁰Tm calibration + XRF
70	Yb	41	7	34	97	56	—	52.231	Stable; XRF Kα₁
71	Lu	40	1	39	95	55	113.0 / 208.4	53.884	¹⁷⁷Lu therapy + XRF
72	Hf	36	5	31	85	49	482.2	55.568	¹⁸¹Hf tracer + XRF
73	Ta	37	1	36	88	51	67.7 / 1221.4 / 1231	57.284	¹⁸²Ta γ emitter + XRF
74	W	35	5	30	83	48	685.8	59.318	¹⁸⁷W tracer + XRF
75	Re	39	1	38	93	54	137.2	61.140	¹⁸⁶Re therapy + XRF
76	Os	35	7	28	83	48	129.4	63.087	Stable + XRF
77	Ir	34	2	32	81	47	316.5 / 468.1 / 604.7	65.145	¹⁹²Ir industrial γ + XRF
78	Pt	35	6	29	83	48	99.0	66.832	¹⁹⁵ᵐPt (lab) + XRF
79	Au	36	1	35	85	49	411.8	68.804	¹⁹⁸Au tracer + XRF
80	Hg	38	7	31	90	52	279.2	70.819	²⁰³Hg environmental + XRF
81	Tl	39	2	37	93	54	2614.5	72.871	²⁰⁸Tl (Th chain) + XRF
82	Pb	43	4	39	102	59	351.9 / 46.5	74.969	²¹⁴Pb, ²¹⁰Pb; XRF
83	Bi	41	0	41	97	56	609.3 / 1120.3 / 1764.5	77.107	²¹⁴Bi γs + XRF
84	Po	42	0	42	100	58	—	79.292	α-emitter; XRF
85	At	39	0	39	93	54	—	81.580	Short-lived α; XRF
86	Rn	39	0	39	93	54	609.3 / 1764.5	83.900	γs via daughters; noble gas
87	Fr	34	0	34	81	47	—	86.300	Short-lived; XRF
88	Ra	34	0	34	81	47	186.2	88.800	²²⁶Ra tracer + XRF
89	Ac	33	0	33	78	45	911.2	91.400	²²⁸Ac fission chain + XRF
90	Th	31	1	30	74	43	238.6 / 2614.5	94.000	Th-series γs + XRF
91	Pa	29	0	29	69	40	312.0	96.700	²³³Pa intermediate + XRF
92	U	28	0	28	66	38	1001.0	98.439	²³⁴mPa (U-series) + XRF

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