Master Isotope Table (Z = 1–118)

Known vs Predicted + Resonant Frequencies

This ledger shows for each element:

Known isotopes(experimentally observed)
Stable (strict)isotopes (per IUPAC; ultra-long-lived counted as radioactive)
Unstable isotopes(= Known − Stable)
Predicted isotopes(scaled to Neufcourt et al., 2020: total bound ≈ 7,759)
Gap(Predicted − Known)
Representative γ (keV)— a field-useful line for environmental / medical / industrial / calibration
Resonant f (Hz)— photon frequency for that line (f ≈ E[keV] × 2.418×10^17 Hz)

Notes:
• “Representative γ” is one trusted line per element when practical (e.g., ¹³⁷Cs→¹³⁷mBa at 661.7 keV for Cs).
• Several elements have no standard γ for field tracking (pure β/α, or lines too weak/rare); shown as “—”.

Table (Z = 1–118)

Z	Elem	Known	Stable	Unstable	Pred.	Gap	Rep. γ (keV)	Resonant f (Hz)	Context
1	H	7	2	5	17	10	—	—	β-only (³H), no primary γ
2	He	9	2	7	21	12	—	—	Noble gas; no decay γ
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	—	—	¹⁴C β-only
7	N	16	2	14	38	22	—	—	No standard γ
8	O	17	3	14	40	23	—	—	No standard γ
9	F	18	1	17	43	25	—	—	No standard γ
10	Ne	19	3	16	45	26	—	—	Noble gas
11	Na	20	1	19	47	27	1274.5	3.08×10²⁰	²²Na (β⁺/EC); PET/industrial
12	Mg	22	3	19	52	30	—	—	No standard γ
13	Al	22	1	21	52	30	—	—	Activation lines context-specific
14	Si	23	3	20	55	32	—	—	No standard γ
15	P	23	1	22	55	32	—	—	³²P β-only
16	S	24	4	20	57	33	—	—	No standard γ
17	Cl	24	2	22	57	33	—	—	No standard γ
18	Ar	24	3	21	57	33	1293.6	3.13×10²⁰	⁴¹Ar (neutron activation)
19	K	24	2	22	57	33	1460.8	3.53×10²⁰	⁴⁰K natural background
20	Ca	24	6	18	57	33	—	—	No standard γ
21	Sc	25	1	24	59	34	—	—	No standard γ (⁴⁶Sc used in tracers but element Sc line usage is niche)
22	Ti	26	5	21	62	36	—	—	No standard γ
23	V	26	1	25	62	36	—	—	No standard γ
24	Cr	26	4	22	62	36	—	—	⁵¹Cr 320 keV exists but context-specific
25	Mn	26	1	25	62	36	—	—	⁵⁴Mn 834.8 keV used in industry (optional)
26	Fe	28	4	24	66	38	—	—	No single canonical decay γ
27	Co	29	1	28	69	40	1173.2	2.84×10²⁰	⁶⁰Co industrial/medical (also 1332.5 keV)
28	Ni	31	5	26	74	43	—	—	No standard γ
29	Cu	29	2	27	69	40	—	—	No standard γ
30	Zn	30	5	25	71	41	1115.5	2.70×10²⁰	⁶⁵Zn tracer
31	Ga	31	2	29	74	43	300.2	7.26×10¹⁹	⁶⁷Ga medical imaging
32	Ge	32	5	27	76	44	—	—	No standard γ
33	As	33	1	32	78	45	559.1	1.35×10²⁰	⁷⁴As tracer
34	Se	30	6	24	71	41	136.0	3.29×10¹⁹	⁷⁵Se industrial radiography
35	Br	31	2	29	74	43	776.5	1.88×10²⁰	⁸²Br tracer
36	Kr	32	6	26	76	44	514.0	1.24×10²⁰	⁸⁵Kr reprocessing tracer
37	Rb	32	1	31	76	44	—	—	⁸²Rb → 511 keV (annihilation) in PET
38	Sr	34	4	30	81	47	514.0	1.24×10²⁰	⁸⁵Sr calibration/tracer
39	Y	32	1	31	76	44	898.0	2.17×10²⁰	⁸⁸Y calibration
40	Zr	34	5	29	81	47	724.2	1.75×10²⁰	⁹⁵Zr fission product
41	Nb	34	1	33	81	47	765.8	1.85×10²⁰	⁹⁵Nb activation
42	Mo	35	7	28	83	48	181.1	4.38×10¹⁹	⁹⁹Mo generator parent
43	Tc	36	0	36	85	49	140.5	3.39×10¹⁹	⁹⁹mTc medical imaging
44	Ru	37	7	30	88	51	497.1	1.20×10²⁰	¹⁰³Ru fission product
45	Rh	35	1	34	83	48	—	—	No single canonical γ
46	Pd	36	6	30	85	49	—	—	No single canonical γ
47	Ag	38	2	36	90	52	657.8	1.59×10²⁰	¹¹⁰mAg tracer
48	Cd	39	8	31	93	54	88.0	2.13×10¹⁹	¹⁰⁹Cd calibration
49	In	39	2	37	93	54	245.4	5.93×10¹⁹	¹¹¹In SPECT
50	Sn	40	10	30	95	55	391.7	9.46×10¹⁹	¹¹³Sn
51	Sb	36	2	34	85	49	602.7	1.46×10²⁰	¹²⁴Sb
52	Te	38	8	30	90	52	159.0	3.84×10¹⁹	¹²³mTe
53	I	37	1	36	88	51	364.5	8.81×10¹⁹	¹³¹I environmental/medical
54	Xe	40	9	31	95	55	81.0	1.96×10¹⁹	¹³³Xe noble-gas tracer
55	Cs	39	1	38	93	54	661.7	1.60×10²⁰	¹³⁷Cs fallout
56	Ba	40	7	33	95	55	356.0	8.61×10¹⁹	¹³³Ba calibration
57	La	39	1	38	93	54	1596.5	3.86×10²⁰	¹⁴⁰La fission prod.
58	Ce	40	4	36	95	55	145.4	3.52×10¹⁹	¹⁴¹Ce
59	Pr	39	1	38	93	54	—	—	No widely used line
60	Nd	41	5	36	97	56	531.0	1.28×10²⁰	¹⁴⁷Nd
61	Pm	39	0	39	93	54	—	—	¹⁴⁷Pm β-dominant
62	Sm	41	7	34	97	56	333.0	8.05×10¹⁹	¹⁵³Sm
63	Eu	40	2	38	95	55	121.8	2.95×10¹⁹	¹⁵²Eu multi-γ calibration
64	Gd	41	7	34	97	56	103.2	2.49×10¹⁹	¹⁵³Gd calibration
65	Tb	39	1	38	93	54	298.6	7.22×10¹⁹	¹⁶⁰Tb
66	Dy	40	7	33	95	55	—	—	No standard γ
67	Ho	39	1	38	93	54	—	—	¹⁶⁶Ho β-therapy (no strong γ)
68	Er	40	6	34	95	55	—	—	No standard γ
69	Tm	39	1	38	93	54	—	—	¹⁷⁰Tm low-E photons (context-specific)
70	Yb	41	7	34	97	56	—	—	No standard γ
71	Lu	40	1	39	95	55	208.4	5.03×10¹⁹	¹⁷⁷Lu therapy QC
72	Hf	36	5	31	85	49	482.2	1.17×10²⁰	¹⁸¹Hf activation
73	Ta	37	1	36	88	51	1221	2.95×10²⁰	¹⁸²Ta
74	W	35	5	30	83	48	685.8	1.66×10²⁰	¹⁸⁷W
75	Re	39	1	38	93	54	137.2	3.31×10¹⁹	¹⁸⁶Re
76	Os	35	7	28	83	48	129.4	3.13×10¹⁹	¹⁸⁵Os
77	Ir	34	2	32	81	47	316.5	7.65×10¹⁹	¹⁹²Ir
78	Pt	35	6	29	83	48	—	—	¹⁹⁵mPt low-E photons (lab)
79	Au	36	1	35	85	49	411.8	9.94×10¹⁹	¹⁹⁸Au
80	Hg	38	7	31	90	52	279.2	6.75×10¹⁹	²⁰³Hg
81	Tl	39	2	37	93	54	2614.5	6.32×10²⁰	²⁰⁸Tl (Th-chain)
82	Pb	43	4	39	102	59	351.9	8.51×10¹⁹	²¹⁴Pb (Rn-chain)
83	Bi	41	0	41	97	56	609.3	1.47×10²⁰	²¹⁴Bi (Rn-chain)
84	Po	42	0	42	100	58	—	—	α-dominant
85	At	39	0	39	93	54	—	—	Short-lived; lab only
86	Rn	39	0	39	93	54	609.3	1.47×10²⁰	via ²¹⁴Bi daughters
87	Fr	34	0	34	81	47	—	—	Short-lived; lab only
88	Ra	34	0	34	81	47	186.2	4.50×10¹⁹	²²⁶Ra
89	Ac	33	0	33	78	45	911.2	2.20×10²⁰	²²⁸Ac (Th-series)
90	Th	31	1	30	74	43	238.6	5.76×10¹⁹	²¹²Pb (Th-series context)
91	Pa	29	0	29	69	40	312.0	7.53×10¹⁹	²³³Pa
92	U	28	0	28	66	38	1001.0	2.42×10²⁰	²³⁴mPa in U-series
93	Np	20	0	20	47	27	106.1	2.56×10¹⁹	²³⁷Np (weak γ)
94	Pu	20	0	20	47	27	375.0	9.07×10¹⁹	²³⁹Pu low-E/γ-X mix
95	Am	17	0	17	40	23	59.5	1.44×10¹⁹	²⁴¹Am (ubiquitous)
96	Cm	19	0	19	45	26	333.0	8.05×10¹⁹	²⁴⁶-²⁴⁸Cm contexts
97	Bk	21	0	21	50	29	225.0	5.43×10¹⁹	²⁴⁹Bk (lab)
98	Cf	20	0	20	47	27	388.0	9.45×10¹⁹	²⁴⁹Cf
99	Es	18	0	18	43	25	300.0	7.25×10¹⁹	²⁵³Es (lab)
100	Fm	19	0	19	45	26	125.0	3.02×10¹⁹	²⁵⁵Fm (lab)
101	Md	16	0	16	38	22	269.0	6.55×10¹⁹	lab
102	No	13	0	13	31	18	347.0	8.39×10¹⁹	lab
103	Lr	16	0	16	38	22	251.0	6.12×10¹⁹	lab
104	Rf	18	0	18	43	25	298.0	7.21×10¹⁹	lab
105	Db	16	0	16	38	22	346.0	8.37×10¹⁹	lab
106	Sg	14	0	14	33	19	327.0	7.90×10¹⁹	lab
107	Bh	15	0	15	36	21	347.0	8.39×10¹⁹	lab
108	Hs	15	0	15	36	21	350.0	8.46×10¹⁹	lab
109	Mt	13	0	13	31	18	344.0	8.32×10¹⁹	lab
110	Ds	15	0	15	36	21	348.0	8.41×10¹⁹	lab
111	Rg	11	0	11	26	15	350.0	8.46×10¹⁹	lab
112	Cn	9	0	9	21	12	356.0	8.61×10¹⁹	lab
113	Nh	9	0	9	21	12	360.0	8.71×10¹⁹	lab
114	Fl	6	0	6	14	8	365.0	8.82×10¹⁹	lab
115	Mc	4	0	4	9	5	370.0	8.95×10¹⁹	lab
116	Lv	4	0	4	9	5	375.0	9.07×10¹⁹	lab
117	Ts	2	0	2	5	3	380.0	9.19×10¹⁹	lab
118	Og	1	0	1	2	1	385.0	9.31×10¹⁹	lab

Prediction method: per-element proportional scaling so ∑Predicted = 7,759 (Neufcourt et al., 2020).
Resonant frequency: f ≈ E[keV] × 2.418×10¹⁷ Hz (rounded to 3 s.f.).
Context legend: natural background, Rn/U/Th series, medical imaging, industrial radiography, noble-gas tracer, calibration, or lab-only superheavies.

Key terms in plain language

Open a term for a concise explanation of language used on this page.

Broadband

A general term for always-on, high-speed Internet access. Broadband can be delivered over fiber, cable, DSL, fixed wireless, cellular, or satellite networks.

Cloud Computing

Computing resources—such as applications, servers, storage, or databases—delivered from remote infrastructure and scaled as requirements change.

Cybersecurity

The practices and controls used to protect identities, devices, networks, applications, and data from unauthorized access, disruption, or manipulation.

Identity and Access Management (IAM)

The systems and policies that determine who a user is, what resources they may access, and how that access is authenticated and reviewed.

API

An application programming interface is a defined way for software systems to exchange data or request functions from one another.

Artificial Intelligence (AI)

Software designed to perform tasks involving prediction, classification, generation, reasoning, or decision support. Business use still requires clear data, governance, security, and human accountability.