Meitnerium (Mt)

Unknown

Meitnerium is a superheavy element named after Lise Meitner, who explained nuclear fission, and with [Rn] 5f¹⁴ 6d⁷ 7s², meitnerium (half-life 4.5 seconds for Mt-278) is expected to be more reactive than iridium. It has been produced in only a few dozen atoms since its discovery in 1982.

Key metrics

Density22g/cm³predicted

Melting point2,600Kpredicted

Boiling point4,600Kpredicted

Electronegativity1.3Paulingpredicted

Discovery

1982discovered

Discovered by: GSI Darmstadt
Reactivity profile: Insufficient data
Reactivity: Unknown
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Rn]}\; \textcolor{#a855f7}{5_{f}^{14}}\; \textcolor{#22c55e}{6_{d}^{7}}\; \textcolor{#ef4444}{7_{s}^{2}}

[Rn] 5f14 6d7 7s2

Wave function

\Psi_{\text{Mt}} \approx \frac{1}{\sqrt{109!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{109}(\mathbf{r}_{109}) \right|

Probability density $|\Psi|^2$ across the Mt valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 129 pmpredicted
Ionization energy: 630 kJ/molpredicted
Electron affinity: 0 kJ/molpredicted
Crystal structure: Hexagonal close-packed (predicted)

Oxidation statespredicted

Acid/base

Unknown

Strongly acidicStrongly basic

State at 25 °CSolid

2600 K4600 K298 K

predicted

Unknown

Key metrics

Density22g/cm³predicted

Melting point2,600Kpredicted

Boiling point4,600Kpredicted

Electronegativity1.3Paulingpredicted

Discovery

1982discovered

Discovered by: GSI Darmstadt
Reactivity profile: Insufficient data
Reactivity: Unknown
Bonding: Metallic

Electron configuration

\textcolor{#6b7280}{[Rn]}\; \textcolor{#a855f7}{5_{f}^{14}}\; \textcolor{#22c55e}{6_{d}^{7}}\; \textcolor{#ef4444}{7_{s}^{2}}

[Rn] 5f14 6d7 7s2

Wave function

\Psi_{\text{Mt}} \approx \frac{1}{\sqrt{109!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{109}(\mathbf{r}_{109}) \right|

Probability density $|\Psi|^2$ across the Mt valence shell.

Crystal structure

Hexagonal Close-Packed

Lattice constantsa 1.00 · b 1.00 · c 1.63

Cell anglesα 90° · β 90° · γ 120°

Coordination number12

Atoms per cell2

Atomic packing factor0.74

Physical properties

Atomic radius: 129 pmpredicted
Ionization energy: 630 kJ/molpredicted
Electron affinity: 0 kJ/molpredicted
Crystal structure: Hexagonal close-packed (predicted)

Oxidation statespredicted

Acid/base

Unknown

Strongly acidicStrongly basic

State at 25 °CSolid

2600 K4600 K298 K

predicted