Roentgenium (Rg)

Unknown

Roentgenium is a superheavy element expected to share properties with gold but with dramatically different reactivity, and with [Rn] 5f¹⁴ 6d⁹ 7s², roentgenium (half-life 100 seconds for Rg-282) should be more volatile than gold. Its chemistry is largely theoretical—only about 50 atoms have ever been observed.

Key metrics

Density23g/cm³predicted

Melting point2,000Kpredicted

Boiling point4,200Kpredicted

Electronegativity1.3Paulingpredicted

Discovery

1994discovered

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}^{9}}\; \textcolor{#ef4444}{7_{s}^{2}}

[Rn] 5f14 6d9 7s2

Wave function

\Psi_{\text{Rg}} \approx \frac{1}{\sqrt{111!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{111}(\mathbf{r}_{111}) \right|

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

Crystal structure

Face-Centered Cubic

Lattice constantsa = 1.00

Cell anglesα = β = γ = 90°

Coordination number12

Atoms per cell4

Atomic packing factor0.74

Physical properties

Atomic radius: 121 pmpredicted
Ionization energy: 650 kJ/molpredicted
Electron affinity: 0 kJ/molpredicted
Crystal structure: Face-centered cubic (predicted)

Oxidation statespredicted

+1+3

Acid/base

Unknown

Strongly acidicStrongly basic

State at 25 °CSolid

2000 K4200 K298 K

predicted

Unknown

Key metrics

Density23g/cm³predicted

Melting point2,000Kpredicted

Boiling point4,200Kpredicted

Electronegativity1.3Paulingpredicted

Discovery

1994discovered

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}^{9}}\; \textcolor{#ef4444}{7_{s}^{2}}

[Rn] 5f14 6d9 7s2

Wave function

\Psi_{\text{Rg}} \approx \frac{1}{\sqrt{111!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{111}(\mathbf{r}_{111}) \right|

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

Crystal structure

Face-Centered Cubic

Lattice constantsa = 1.00

Cell anglesα = β = γ = 90°

Coordination number12

Atoms per cell4

Atomic packing factor0.74

Physical properties

Atomic radius: 121 pmpredicted
Ionization energy: 650 kJ/molpredicted
Electron affinity: 0 kJ/molpredicted
Crystal structure: Face-centered cubic (predicted)

Oxidation statespredicted

+1+3

Acid/base

Unknown

Strongly acidicStrongly basic

State at 25 °CSolid

2000 K4200 K298 K

predicted