Notation. Nuclides are written with the mass number as a left superscript (e.g., ²⁷⁸Mt).
Columns. Stable? — Meitnerium has no stable isotopes. Half-lives = evaluated values. Decay → daughter(s) shows main branches. Radiation: α, SF (spontaneous fission), EC (electron capture). Origin: all isotopes are synthetic. Uses: R research only.
Primary data spine: evaluated Isotopes of meitnerium (ENSDF/NUBASE 2020).
Table — ground states
| Nuclide | Z | A | Stable? | Half-life | Decay → daughter(s) | Radiation | Origin | Notes & Uses |
|---|---|---|---|---|---|---|---|---|
| ²⁶⁵Mt | 109 | 265 | No | ~0.7 ms | α → ²⁶¹Bh | α | Fusion-evap. | R. |
| ²⁶⁶Mt | 109 | 266 | No | ~1.0 ms | α → ²⁶²Bh | α | Synthetic | R. |
| ²⁶⁷Mt | 109 | 267 | No | ~5 ms | α → ²⁶³Bh | α | Synthetic | R. |
| ²⁶⁸Mt | 109 | 268 | No | 21 ms | α → ²⁶⁴Bh | α | Synthetic | R. |
| ²⁶⁹Mt | 109 | 269 | No | 70 ms | α → ²⁶⁵Bh | α | Synthetic | R. |
| ²⁷⁰Mt | 109 | 270 | No | 0.7 s | α → ²⁶⁶Bh | α | Synthetic | R. |
| ²⁷¹Mt | 109 | 271 | No | 1.3 s | α → ²⁶⁷Bh | α | Synthetic | R. |
| ²⁷²Mt | 109 | 272 | No | 1.9 s | α → ²⁶⁸Bh | α | Synthetic | R. |
| ²⁷³Mt | 109 | 273 | No | 0.7 s | α → ²⁶⁹Bh | α | Synthetic | R. |
| ²⁷⁴Mt | 109 | 274 | No | 0.44 s | α → ²⁷⁰Bh | α | Synthetic | R. |
| ²⁷⁵Mt | 109 | 275 | No | 0.62 s | α → ²⁷¹Bh | α | Synthetic | R. |
| ²⁷⁶Mt | 109 | 276 | No | 0.72 s | α → ²⁷²Bh | α | Synthetic | R. |
| ²⁷⁷Mt | 109 | 277 | No | 0.7 ms | SF (dominant) | SF | Synthetic | R. |
| ²⁷⁸Mt | 109 | 278 | No | 4.0 s | α → ²⁷⁴Bh | α | Synthetic (GSI, JINR) | Longest-lived isotope, used in chemistry studies. |
Natural isotopes of meitnerium
- None.
- All isotopes are synthetic, first produced at GSI Darmstadt in 1982 by bombarding bismuth-209 with iron-58.
Applied & research highlights
- ²⁷⁸Mt (4 s): longest-lived isotope, enabled first chemical studies of Mt in the early 2000s.
- Meitnerium is in Group 9 of the periodic table, predicted to behave like iridium, but its chemistry is still largely unexplored due to extreme rarity.
- Only produced in atom-at-a-time quantities.
- No practical applications beyond fundamental nuclear and chemical research.
Totals — Meitnerium (Z = 109)
- Ground-state isotopes listed14 (A = 265–278).
- Stable0.
- Unstable14.
Running cumulative totals (through Mt):
From Hs ledger: ≥ 3 267 total, 252 stable, ≥ 3 014 unstable.
Add Mt (+14 total, +0 stable, +14 unstable) → ≥ 3 281 total, 252 stable, ≥ 3 028 unstable.
Sources
- Isotopic list (A = 265–278)Isotopes of meitnerium (ENSDF/NUBASE 2020).
- Discovery (1982, GSI Darmstadt)first produced in Bi-209 + Fe-58 fusion.
- Chemistry studies (²⁷⁸Mt)transactinide gas-phase experiments.
Next element: Darmstadtium — Ds (Z = 110).
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.