Physical Properties
How this element behaves in real-world conditions.
- State (25°C)
- Solid
- Density
- 4.93 g/cm³
- Melting Point
- 113.7 °C
- Boiling Point
- 184.3 °C
Atomic Structure
Core identity and periodic table positioning.
Electromagnetic Properties
How this element attracts and exchanges electrons.
- Electronegativity
- 2.66
- Ionization Energy
- 10.451 eV
- Electron Affinity
- 3.059 eV
- Metallic Character
- Nonmetal
Hero / Identity Section
Core identity profile for Iodine with periodic placement and electron context.
- Element Name
- Iodine
- Symbol
- I
- Atomic Number
- 53
- Atomic Mass
- 126.9
- Group
- 17
- Period
- 5
- Block
- P
- Category
- Halogen
- Standard State
- Solid
- Electron Configuration (Full)
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p5
- Electron Configuration (Noble Gas)
- [Kr] 5s2 4d10 5p5
- Valence Electrons
- 7
Quick Facts Card (Table Layout)
Fast-reference values for physical and energetic properties.
Atomic Radius
115 pm
Ionic Radius
Not available in current dataset
Electronegativity (Pauling)
2.66
1st Ionization Energy
10.451 eV
Electron Affinity
3.059 eV
Density
4.93 g/cm³
Melting Point
113.7 °C
Boiling Point
184.3 °C
Heat Capacity
Not available in current dataset
Thermal Conductivity
Not available in current dataset
Visual Components
Visual learning views for table position, shells, orbitals, and phase behavior.
Highlighted Position in Periodic Table Grid
I
Row 5, Column 17
Bohr Model Diagram
I
Educational shell model for electron arrangement.
Electron Shell Diagram
- K shell2
- L shell8
- M shell18
- N shell18
- O shell7
Orbital Configuration Diagram
1s2/2
2s2/2
2p6/6
3s2/2
3p6/6
4s2/2
3d10/10
4p6/6
5s2/2
4d10/10
5p5/6
Phase Illustration
Solid
Solid lattice
Atomic Structure Section
Nuclear composition and electron shielding interpretation.
- Protons
- 53
- Neutrons (Most Abundant Isotope Estimate)
- 74
- Electrons
- 53
- Electron Configuration Breakdown
- 2 • 8 • 18 • 18 • 7
- Shielding Explanation
- Core electrons (~46) shield part of the nucleus, reducing attraction felt by outer electrons compared with the full nuclear charge.
- Effective Nuclear Charge (Estimate)
- 7
Chemical Properties Section
Category-guided chemistry behavior with periodic context for comparison.
- Common Oxidation States
- -1 (common), also positive states in oxy-compounds
- Reactivity Summary
- Highly reactive nonmetals; strong oxidizers in many forms.
- Acid/Base Behavior
- Forms strong acids and acidic oxy-compounds in many reaction pathways.
- Bonding Behavior
- Mostly covalent in molecular form; ionic salts with metals are common.
- Typical Compounds
- NaI, I2, KI
- Periodic Trend Comparison (Group Neighbors)
- Compared with Br, this element is lower in the group and typically has a larger atomic size and lower ionization tendency. Compared with At, this element is higher in the group and often shows a smaller radius with stronger effective attraction to valence electrons.
Isotopes & Nuclear Data
Isotope stability and abundance notes for learning-oriented nuclear context.
- Stable Isotopes
- Stable isotopes are known. Most abundant isotope is commonly represented near I-127.
- Radioactive Isotopes
- Radioactive isotopes exist alongside stable isotopes.
- Natural Abundance (%)
- Naturally occurring with isotope-dependent abundance.
- Half-life (If Applicable)
- Stable isotopes have no half-life; radioactive isotopes have isotope-specific half-lives.
- Nuclear Spin (Optional Advanced)
- Advanced isotope-level data is not included in the current core dataset.
- Most Abundant Isotope (Estimate)
- I-127
Applications & Uses
How this element appears in industry, biology, medicine, and technology.
- Industrial Uses
- Used in disinfection, polymers, etching, and synthetic chemistry.
- Biological Role
- Specific halide ions have physiological relevance in small amounts.
- Medical Use
- Disinfectants, imaging agents, and medicinal salts/compounds.
- Technological Relevance
- Important in electronics etching, refrigerants, and specialty materials.
- Environmental Impact
- Can form persistent/ozone-active species depending on chemistry.
Safety & Handling
General hazard guidance for educational reference and lab awareness.
- Toxicity
- Elemental forms and concentrated compounds can be highly toxic/corrosive.
- Flammability
- Not typically fuels; many forms are strong oxidizers that intensify combustion.
- Storage Considerations
- Use corrosion-resistant sealed storage with ventilation and segregation.
- Regulatory Classification
- Commonly regulated as toxic/corrosive/oxidizing materials.