Reactivity & Chemical Bonding
Chemical Behavior & Oxidation States
Actinium exhibits chemical reactivity characteristic of the actinide family, governed by an electronegativity of 1.1 and standard valence interactions.
Z = 89Actinide
Launch 3D Atom & Orbitals LabActinium
Ac
Standard Atomic Mass: 227 u
Period 7Group 3F-Block
Chemical Specimen/Ac
Concentric Electron Shells7 Energy Levels
n=1: 2e⁻→
n=2: 8e⁻→
n=3: 18e⁻→
n=4: 32e⁻→
n=5: 19e⁻→
n=6: 8e⁻→
n=7: 2e⁻
Scientific Monograph • Actinide
3D Atom SimulatorActinium (Ac) Scientific Profile
Actinium (Ac) is an element with atomic number 89, classified as a actinide. Positioned in Period 7, Group 3, and F-block, its chemical and physical profile is defined by its electron configuration ([Rn]6d¹7s²) and periodic trends.
Interactive Virtual Labs Available for Actinium
3D Orbitals & Valence Lab
Simulate concentric quantum energy levels, observe valence electron spins, and examine live atomic clouds in full 3D.
Electronic Configuration Lab
Experiment with Aufbau subshell ordering, explore orbital occupancy, and analyze quantum configuration exceptions.
Electron Config
[Rn]6d¹7s²
Electronegativity
1.1 Pauling
Year Discovered
Ancient Era
Orbital Shells
7 Principal Levels
Orbital Block
f-block orbital
Group / Period
G: 3 • P: 7
Technological Utility
Industrial & Energy Applications
Actinium is utilized in industrial fabrication, materials engineering, electronic manufacturing, and advanced laboratory research based on its specific thermodynamic properties.
Biological Role
Biomedical Profile & Toxicity
Actinium does not play a prominent biological role in human biochemistry, existing primarily as a trace element or mineral component in natural ecosystems.
Geochemistry & Abundance
Cosmic & Terrestrial Occurrence
Elements like Actinium are synthesized through stellar nucleosynthesis and supernovae r-processes. On Earth, Actinium is concentrated in specific ore deposits or synthesized in nuclear accelerators.
Frequently Asked Questions about Actinium
Q
What are the key physical and atomic properties of Actinium?
Actinium (Ac) has an atomic number of 89 and a standard atomic mass of 227 u. It is positioned in Period 7, Group 3, in the F-block, and is classified within the Actinide category.
Q
What is the electron configuration of Actinium?
The ground-state electron configuration of Actinium is [Rn]6d¹7s². Its 89 electrons are distributed across 7 principal energy levels (2, 8, 18, 32, 19, 8, 2).
Q
Why does Actinium exhibit an electron configuration exception?
Actinium follows standard Aufbau principle orbital filling. Transition metals and heavy elements optimize their shell filling based on subshell exchange energy and electrostatic stability.
Q
What are the primary commercial and laboratory uses of Actinium?
Actinium is utilized in industrial fabrication, materials engineering, electronic manufacturing, and advanced laboratory research based on its specific thermodynamic properties.