Element: Copper
General data
| Element name | Copper |
|---|---|
| Chemical symbol | Cu |
| Atomic number Z | 29 |
| Year discovered | known since antiquity |
| Standard state (25°C) | Solid |
| Category | Transition metal |
| Block | d |
| Atomic mass | 63.546 |
| CPK color | #C88033 |
Physical properties
| Melting point | 1357.77 K (1084.62 °C) |
|---|---|
| Boiling point | 2835 K (2562 °C) |
| Density | 8.933 g/cm³ |
Energy properties
| First ionization energy | 7.726 eV |
|---|---|
| Electron affinity | 1.228 eV |
Atomic structure
| Protons | 29 (Atomic number) |
|---|---|
| Neutrons (Cu-63, most abundant isotope) | 34 |
| Electrons | 29 |
| Electron configuration | [Ar] 4s¹ 3d¹⁰ |
| Oxidation states | +2, +1 |
| Electronegativity (Pauling) | 1.9 |
| Atomic radius (van der Waals) | 140 pm |
Ionization energies - NIST ASD (29 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| Cu I | 0+ | 7.72638 ± 0.000004 | measured |
| Cu II | 1+ | 20.29239 ± 0.00006 | measured |
| Cu III | 2+ | 36.841 ± 0.012 | measured |
| Cu IV | 3+ | 57.38 ± 0.05 | semi-empirical |
| Cu V | 4+ | 79.8 ± 0.7 | semi-empirical |
| Cu VI | 5+ | 103 ± 1 | semi-empirical |
| Cu VII | 6+ | 139 ± 1.2 | semi-empirical |
| Cu VIII | 7+ | 166 ± 2.1 | calculated |
| Cu IX | 8+ | 198 ± 2.2 | calculated |
| Cu X | 9+ | 232.2 ± 0.5 | semi-empirical |
| Cu XI | 10+ | 265.33 ± 0.25 | measured |
| Cu XII | 11+ | 367 ± 0.9 | semi-empirical |
| Cu XIII | 12+ | 401 ± 0.3 | semi-empirical |
| Cu XIV | 13+ | 436 ± 0.6 | semi-empirical |
| Cu XV | 14+ | 483.1 ± 0.9 | semi-empirical |
| Cu XVI | 15+ | 518.7 ± 1.2 | semi-empirical |
| Cu XVII | 16+ | 552.8 ± 2.1 | semi-empirical |
| Cu XVIII | 17+ | 632.5 ± 0.6 | semi-empirical |
| Cu XIX | 18+ | 670.608 ± 0.02 | semi-empirical |
| Cu XX | 19+ | 1690.5 ± 0.9 | semi-empirical |
| Cu XXI | 20+ | 1800 ± 3 | semi-empirical |
| Cu XXII | 21+ | 1918 ± 4 | semi-empirical |
| Cu XXIII | 22+ | 2044 ± 6 | semi-empirical |
| Cu XXIV | 23+ | 2179.4 ± 1.5 | semi-empirical |
| Cu XXV | 24+ | 2307.3 ± 1 | semi-empirical |
| Cu XXVI | 25+ | 2479.1 ± 2.2 | semi-empirical |
| Cu XXVII | 26+ | 2586.954 ± 0.007 | calculated |
| Cu XXVIII | 27+ | 11062.4309 ± 0.0011 | calculated |
| Cu XXIX | 28+ | 11567.6237 ± 0.0005 | calculated |
Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.
Photos
Isotopes (31)
| A | N | Half-life | Decay |
|---|---|---|---|
| Cu-53 | 24 | < 130 ns | p |
| Cu-54 | 25 | < 75 ns | p |
| Cu-55 | 26 | 55.9 ms | EC/β⁺ |
| Cu-56 | 27 | 80.8 ms | EC/β⁺ |
| Cu-57 | 28 | 196.4 ms | EC/β⁺ |
| Cu-58 | 29 | 3.205 s | EC/β⁺ |
| Cu-59 | 30 | 82.0 s | EC/β⁺ |
| Cu-60 | 31 | 23.7 min | EC/β⁺ |
| Cu-61 | 32 | 3.339 h | EC/β⁺ |
| Cu-62 | 33 | 9.672 min | EC/β⁺ |
| Cu-63 | 34 | stable | - |
| Cu-64 | 35 | 12.7007 h | β⁻ |
| Cu-65 | 36 | stable | - |
| Cu-66 | 37 | 5.090 min | β⁻ |
| Cu-67 | 38 | 61.81 h | β⁻ |
| Cu-68 | 39 | 30.8 s | β⁻ |
| Cu-69 | 40 | 2.9 min | β⁻ |
| Cu-70 | 41 | 44.5 s | β⁻ |
| Cu-71 | 42 | 19.4 s | β⁻ |
| Cu-72 | 43 | 6.63 s | β⁻ |
| Cu-73 | 44 | 4.20 s | β⁻ |
| Cu-74 | 45 | 1.606 s | β⁻ |
| Cu-75 | 46 | 1.224 s | β⁻ |
| Cu-76 | 47 | 637 ms | β⁻ |
| Cu-77 | 48 | 469.8 ms | β⁻ |
| Cu-78 | 49 | 331.3 ms | β⁻ |
| Cu-79 | 50 | 241 ms | β⁻ |
| Cu-80 | 51 | 113 ms | β⁻ |
| Cu-81 | 52 | 73 ms | β⁻ |
| Cu-82 | 53 | 33 ms | β⁻ |
| Cu-83 | 54 | unknown | β⁻ |
Data sources
- PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
- IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
- NIST Atomic Spectra Database (ASD) - Retrieved on 29 June 2026 - licence: © U.S. Secretary of Commerce
- Images of Elements - Retrieved on 29 June 2026 - licence: CC BY 3.0