Reactivity & Chemical Bonding
Chemical Behavior & Oxidation States
Protactinium exhibits chemical reactivity characteristic of the actinide family, governed by an electronegativity of 1.5 and standard valence interactions.
Z = 91Actinide
Launch 3D Atom & Orbitals LabProtactinium
Pa
Standard Atomic Mass: 231.04 u
Period 7Group 3F-Block
Chemical Specimen/Pa
Concentric Electron Shells7 Energy Levels
n=1: 2e⁻→
n=2: 8e⁻→
n=3: 18e⁻→
n=4: 32e⁻→
n=5: 21e⁻→
n=6: 8e⁻→
n=7: 2e⁻
Scientific Monograph • Actinide
3D Atom SimulatorProtactinium (Pa) Scientific Profile
Protactinium (Pa) is an element with atomic number 91, 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]5f²6d¹7s²) and periodic trends.
Interactive Virtual Labs Available for Protactinium
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]5f²6d¹7s²
Electronegativity
1.5 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
Protactinium is utilized in industrial fabrication, materials engineering, electronic manufacturing, and advanced laboratory research based on its specific thermodynamic properties.
Biological Role
Biomedical Profile & Toxicity
Protactinium 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 Protactinium are synthesized through stellar nucleosynthesis and supernovae r-processes. On Earth, Protactinium is concentrated in specific ore deposits or synthesized in nuclear accelerators.
Frequently Asked Questions about Protactinium
Q
What are the key physical and atomic properties of Protactinium?
Protactinium (Pa) has an atomic number of 91 and a standard atomic mass of 231.04 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 Protactinium?
The ground-state electron configuration of Protactinium is [Rn]5f²6d¹7s². Its 91 electrons are distributed across 7 principal energy levels (2, 8, 18, 32, 21, 8, 2).
Q
Why does Protactinium exhibit an electron configuration exception?
Protactinium 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 Protactinium?
Protactinium is utilized in industrial fabrication, materials engineering, electronic manufacturing, and advanced laboratory research based on its specific thermodynamic properties.