Carbon Element Properties
Complete reference for Carbon (C, element 6): atomic data, electron configuration, isotopes, physical constants, allotropes, and chemical behavior.
Carbon
Nonmetal — Period 2, Group 14
Atomic Identity
Electron Configuration
Two unpaired 2p electrons — triplet ground state
Isotopes of Carbon
| Isotope | Symbol | Protons | Neutrons | Mass (u) | Natural Abundance | Stability |
|---|---|---|---|---|---|---|
| Carbon-11 | ¹¹C | 6 | 5 | 11.01143 | Radioactive |
Unstable
β⁺ decay, t½ = 20.4 min |
| Carbon-12 | ¹²C | 6 | 6 | 12.00000 | 98.89% | Stable |
| Carbon-13 | ¹³C | 6 | 7 | 13.00335 | 1.11% | Stable |
| Carbon-14 | ¹⁴C | 6 | 8 | 14.00324 | Trace |
Unstable
β⁻ decay, t½ = 5,730 y |
| Carbon-15 | ¹⁵C | 6 | 9 | 15.01060 | Radioactive |
Unstable
β⁻ decay, t½ = 2.449 s |
Carbon-12 defines the atomic mass unit: by definition, one atom of ¹²C has a mass of exactly 12 u. Carbon-14 is produced cosmogenically and forms the basis of radiocarbon dating.
Physical Properties
Chemical Properties
Ground State Quantum Numbers
Major Allotropes
Key Facts About Carbon
Basis of Organic Chemistry
Carbon forms more compounds than any other element — over 10 million known organic compounds. Its tetravalency and ability to catenate (chain C–C bonds) allow construction of molecules from methane (CH₄) to proteins and DNA.
Mass Standard (Carbon-12)
By international agreement (IUPAC), the atomic mass unit (u) is defined as exactly 1/12 the mass of a single ¹²C atom. This makes carbon-12 the reference anchor for all atomic and molecular mass measurements.
Radiocarbon Dating (¹⁴C)
Cosmic rays produce ¹⁴C in the atmosphere, which enters the food chain. After death the ¹⁴C/¹²C ratio decays at a known rate (t½ = 5,730 years). This allows archaeologists and geologists to date organic material up to ~50,000 years old.
Diamond Superlatives
Diamond is the hardest naturally occurring mineral (Mohs 10), has the highest thermal conductivity of any bulk material (up to 2,320 W/(m·K)), and has an extremely wide optical bandgap (5.5 eV), making it transparent from UV to far infrared.
Global Carbon Cycle
Carbon cycles through the atmosphere (CO₂), oceans (carbonate/bicarbonate), biosphere (organic matter), and lithosphere (limestone, coal, oil). Human combustion of fossil fuels currently releases ~37 billion tonnes of CO₂ per year, disrupting this cycle.
Industrial Applications
Carbon materials are ubiquitous: steel production (coke), energy storage (graphite anodes in lithium-ion batteries), filtration (activated charcoal), lubrication (graphite), cutting tools (diamond), reinforcement (carbon fiber composites), and electronics (graphene, nanotubes).
Summary
Complete reference for Carbon (C, element 6): atomic data, electron configuration, isotopes, physical constants, allotropes, and chemical behavior.
How it works
- Browse the atomic identity section for symbol, atomic number, and standard atomic weight.
- Check the electron configuration panel for orbital notation and quantum numbers.
- Review the isotopes table for carbon-12, carbon-13, and carbon-14 data including natural abundance.
- Consult the physical properties panel for melting point, density, and state at STP.
- Use the chemical properties section to understand nonmetal behavior and ionization energies.
- Explore the allotropes section to compare diamond, graphite, graphene, and fullerene properties.
Use cases
- Look up carbon constants for chemistry homework or exams.
- Verify atomic data when writing lab reports.
- Reference isotope data for radiocarbon dating or nuclear chemistry.
- Check allotrope properties for materials science or engineering research.
- Teach or learn carbon chemistry and its role in organic compounds.
- Confirm electron configuration before writing molecular orbital diagrams.
- Compare carbon isotopes for geochemistry or environmental science.
- Quick-reference ionization energy for electrochemistry or spectroscopy.