Atomic & Nuclear Data
Atomic masses, ionization energies, electron affinities, spectral line wavelengths, nuclear spins, magnetic moments, and radioactive half-lives for all elements.
Source: NIST ASD; AME 2020; NUBASE 2020
Atomic & Quantum Constants
Bohr radius a₀
| Value | 5.291 772 109 03 × 10⁻¹¹ ± 0.000 000 000 80 × 10⁻¹¹ | m | |
| In ångströms | 0.529 177 210 903 ± 0.000 000 000 080 | Å |
Rydberg constant R∞
| Value | 10 973 731.568 160 ± 0.000 021 | m⁻¹ |
Rydberg energy Ry
| Value | 13.605 693 122 994 ± 0.000 000 000 026 | eV |
Hartree energy Eh
| Value (in eV) | 27.211 386 245 988 ± 0.000 000 000 053 | eV | |
| Value (in J) | 4.359 744 650 54 × 10⁻¹⁸ ± 0.000 000 000 54 × 10⁻¹⁸ | J |
Bohr magneton μB
| Value | 9.274 010 0783 × 10⁻²⁴ ± 0.000 000 0028 × 10⁻²⁴ | J T⁻¹ | |
| Value (in eV/T) | 5.788 381 8060 × 10⁻⁵ ± 0.000 000 0017 × 10⁻⁵ | eV T⁻¹ |
Nuclear magneton μN
| Value | 5.050 783 7461 × 10⁻²⁷ ± 0.000 000 0015 × 10⁻²⁷ | J T⁻¹ | |
| Value (in eV/T) | 3.152 451 258 44 × 10⁻⁸ ± 0.000 000 000 96 × 10⁻⁸ | eV T⁻¹ |
Electron g-factor ge
| Value | −2.002 319 304 360 92 ± 0.000 000 000 000 36 |
Proton g-factor gp (free)
| Value | +5.585 694 689 3 ± 0.000 000 001 6 |
Atomic mass unit u
| Value (in MeV/c²) | 931.494 102 42 ± 0.000 000 28 | MeV c⁻² | |
| Value (in kg) | 1.660 539 066 60 × 10⁻²⁷ ± 0.000 000 000 50 × 10⁻²⁷ | kg |
Electron mass me
| Value | 9.109 383 7015 × 10⁻³¹ ± 0.000 000 0028 × 10⁻³¹ | kg | |
| In atomic mass units | 5.485 799 090 65 × 10⁻⁴ ± 0.000 000 000 16 × 10⁻⁴ | u |
Proton mass mp
| Value | 1.007 276 466 621 ± 0.000 000 000 053 | u |
Neutron mass mn
| Value | 1.008 664 915 95 ± 0.000 000 000 49 | u |
Proton–neutron mass difference mn − mp
| Value | 1.293 332 36 ± 0.000 000 73 | MeV c⁻² |
Classical electron radius re
| Value | 2.817 940 326 2 × 10⁻¹⁵ ± 0.000 000 001 3 × 10⁻¹⁵ | m |
Proton charge radius rp
| Value | 0.8414 ± 0.0019 | fm |
Thomson cross section σT
| Value | 6.652 458 732 × 10⁻²⁹ ± 0.000 000 018 × 10⁻²⁹ | m² |
Fine structure constant α
| Value | 7.297 352 569 3 × 10⁻³ ± 0.000 000 001 1 × 10⁻³ | ||
| As 1/α | 137.035 999 084 ± 0.000 000 021 |
Stefan–Boltzmann constant σ
| Value | 5.670 374 419 184 4... × 10⁻⁸ | W m⁻² K⁻⁴ | exact |
Boltzmann constant kB
| Value | 1.380 649 × 10⁻²³ | J K⁻¹ | exact |
| Value (in eV/K) | 8.617 333 262... × 10⁻⁵ | eV K⁻¹ | exact |
Avogadro constant NA
| Value | 6.022 140 76 × 10²³ | mol⁻¹ | exact |
Hydrogen Atom
Ground state energy E₁
| Value | −13.605 693 | eV |
Ionization energy (1s)
| Value | 13.598 433 eV |
Energy level En
| Formula (Bohr model) | En = −13.6 eV / n² |
Lamb shift (2s₁/₂ − 2p₁/₂)
| Value | 1057.84 ± 0.02 | MHz |
1s–2s two-photon transition
| Frequency | 2 466 061 413 187 035 ± 10 | Hz |
Hydrogen ground state hyperfine splitting
| Frequency | 1 420 405 751.768 0 ± 0.001 0 | Hz | |
| Wavelength (21 cm line) | 21.106 114 ± 0.000 001 | cm |
Deuterium hyperfine splitting
| Frequency | 327 384 352.52 ± 0.08 | Hz |
Hydrogen Lyman α (n=1→2)
| Wavelength (vacuum) | 121.567 nm | ||
| Frequency | 2.467 × 10¹⁵ | Hz |
Hydrogen Balmer α Hα (n=2→3)
| Wavelength (vacuum) | 656.279 nm |
Hydrogen Balmer β Hβ (n=2→4)
| Wavelength (vacuum) | 486.135 nm |
Hydrogen Balmer γ Hγ (n=2→5)
| Wavelength (vacuum) | 434.047 nm |
Hydrogen Balmer δ Hδ (n=2→6)
| Wavelength (vacuum) | 410.174 nm |
Hydrogen Balmer series limit
| Wavelength | 364.601 nm |
Key Spectral Lines
H Lyman series (UV)
| Lyman α n=2→1 | 121.567 | nm | |
| Lyman β n=3→1 | 102.572 | nm | |
| Lyman γ n=4→1 | 97.254 | nm | |
| Lyman δ n=5→1 | 94.974 | nm | |
| Lyman limit | 91.175 | nm |
H Balmer series (vis)
| Hα n=3→2 | 656.279 | nm | |
| Hβ n=4→2 | 486.135 | nm | |
| Hγ n=5→2 | 434.047 | nm | |
| Hδ n=6→2 | 410.174 | nm | |
| Balmer limit | 364.601 | nm |
H Paschen series (NIR)
| Paα n=4→3 | 1875.1 | nm | |
| Paβ n=5→3 | 1281.8 | nm | |
| Paγ n=6→3 | 1093.8 | nm |
Sodium D lines
| D₂ 3p ²P₃/₂ → 3s ²S₁/₂ | 588.995 | nm | |
| D₁ 3p ²P₁/₂ → 3s ²S₁/₂ | 589.592 | nm | |
| Fine-structure splitting ΔE | 0.00211 | eV |
Helium
| He-I 23S₁ → 23P (587.6 nm, yellow) | 587.562 | nm | |
| He-I 21P₁ → 21S₀ (584 nm, UV) | 584.334 | nm |
Calcium (Fraunhofer)
| Ca II K 4s²S → 4p²P₁/₂ | 393.366 | nm | |
| Ca II H 4s²S → 4p²P₃/₂ | 396.847 | nm |
Mercury (Hg)
| UV resonance line | 253.652 | nm | |
| Violet | 404.656 | nm | |
| Blue | 435.833 | nm | |
| Green | 546.074 | nm | |
| Yellow doublet | 576.960 / 579.066 | nm |
Potassium D lines
| D₂ 4p ²P₃/₂ → 4s ²S₁/₂ | 766.700 | nm | |
| D₁ 4p ²P₁/₂ → 4s ²S₁/₂ | 769.897 | nm |
Rubidium D lines
| D₂ 5p ²P₃/₂ → 5s ²S₁/₂ | 780.241 | nm | |
| D₁ 5p ²P₁/₂ → 5s ²S₁/₂ | 794.979 | nm |
Cesium D lines
| D₂ 6p ²P₃/₂ → 6s ²S₁/₂ | 852.347 | nm | |
| D₁ 6p ²P₁/₂ → 6s ²S₁/₂ | 894.593 | nm |
Neon (Ne)
| Orange-red dominant | 585.249 | nm | |
| Orange | 614.306 | nm | |
| Red | 640.225 | nm |
First Ionization Energies — All Elements
First Ionization Energy IE₁
| H (Z=1, Hydrogen) | 13.5984 | eV | |
| He (Z=2, Helium) | 24.5874 | eV | |
| Li (Z=3, Lithium) | 5.3917 | eV | |
| Be (Z=4, Beryllium) | 9.3227 | eV | |
| B (Z=5, Boron) | 8.2980 | eV | |
| C (Z=6, Carbon) | 11.2603 | eV | |
| N (Z=7, Nitrogen) | 14.5341 | eV | |
| O (Z=8, Oxygen) | 13.6181 | eV | |
| F (Z=9, Fluorine) | 17.4228 | eV | |
| Ne (Z=10, Neon) | 21.5645 | eV | |
| Na (Z=11, Sodium) | 5.1391 | eV | |
| Mg (Z=12, Magnesium) | 7.6462 | eV | |
| Al (Z=13, Aluminium) | 5.9858 | eV | |
| Si (Z=14, Silicon) | 8.1517 | eV | |
| P (Z=15, Phosphorus) | 10.4867 | eV | |
| S (Z=16, Sulfur) | 10.3600 | eV | |
| Cl (Z=17, Chlorine) | 12.9676 | eV | |
| Ar (Z=18, Argon) | 15.7596 | eV | |
| K (Z=19, Potassium) | 4.3407 | eV | |
| Ca (Z=20, Calcium) | 6.1132 | eV | |
| Sc (Z=21, Scandium) | 6.5615 | eV | |
| Ti (Z=22, Titanium) | 6.8281 | eV | |
| V (Z=23, Vanadium) | 6.7462 | eV | |
| Cr (Z=24, Chromium) | 6.7665 | eV | |
| Mn (Z=25, Manganese) | 7.4340 | eV | |
| Fe (Z=26, Iron) | 7.9024 | eV | |
| Co (Z=27, Cobalt) | 7.8810 | eV | |
| Ni (Z=28, Nickel) | 7.6398 | eV | |
| Cu (Z=29, Copper) | 7.7264 | eV | |
| Zn (Z=30, Zinc) | 9.3942 | eV | |
| Ga (Z=31, Gallium) | 5.9993 | eV | |
| Ge (Z=32, Germanium) | 7.8994 | eV | |
| As (Z=33, Arsenic) | 9.7886 | eV | |
| Se (Z=34, Selenium) | 9.7524 | eV | |
| Br (Z=35, Bromine) | 11.8138 | eV | |
| Kr (Z=36, Krypton) | 13.9996 | eV | |
| Rb (Z=37, Rubidium) | 4.1771 | eV | |
| Sr (Z=38, Strontium) | 5.6949 | eV | |
| Y (Z=39, Yttrium) | 6.2173 | eV | |
| Zr (Z=40, Zirconium) | 6.6339 | eV | |
| Nb (Z=41, Niobium) | 6.7589 | eV | |
| Mo (Z=42, Molybdenum) | 7.0924 | eV | |
| Tc (Z=43, Technetium) | 7.28 | eV | |
| Ru (Z=44, Ruthenium) | 7.3605 | eV | |
| Rh (Z=45, Rhodium) | 7.4589 | eV | |
| Pd (Z=46, Palladium) | 8.3369 | eV | |
| Ag (Z=47, Silver) | 7.5762 | eV | |
| Cd (Z=48, Cadmium) | 8.9938 | eV | |
| In (Z=49, Indium) | 5.7864 | eV | |
| Sn (Z=50, Tin) | 7.3439 | eV | |
| Sb (Z=51, Antimony) | 8.6084 | eV | |
| Te (Z=52, Tellurium) | 9.0096 | eV | |
| I (Z=53, Iodine) | 10.4513 | eV | |
| Xe (Z=54, Xenon) | 12.1298 | eV | |
| Cs (Z=55, Caesium) | 3.8939 | eV | |
| Ba (Z=56, Barium) | 5.2117 | eV | |
| La (Z=57, Lanthanum) | 5.5769 | eV | |
| Ce (Z=58, Cerium) | 5.5387 | eV | |
| Pr (Z=59, Praseodymium) | 5.4730 | eV | |
| Nd (Z=60, Neodymium) | 5.5250 | eV | |
| Pm (Z=61, Promethium) | 5.582 | eV | |
| Sm (Z=62, Samarium) | 5.6437 | eV | |
| Eu (Z=63, Europium) | 5.6704 | eV | |
| Gd (Z=64, Gadolinium) | 6.1498 | eV | |
| Tb (Z=65, Terbium) | 5.8638 | eV | |
| Dy (Z=66, Dysprosium) | 5.9389 | eV | |
| Ho (Z=67, Holmium) | 6.0215 | eV | |
| Er (Z=68, Erbium) | 6.1077 | eV | |
| Tm (Z=69, Thulium) | 6.1843 | eV | |
| Yb (Z=70, Ytterbium) | 6.2542 | eV | |
| Lu (Z=71, Lutetium) | 5.4259 | eV | |
| Hf (Z=72, Hafnium) | 6.8251 | eV | |
| Ta (Z=73, Tantalum) | 7.5496 | eV | |
| W (Z=74, Tungsten) | 7.8640 | eV | |
| Re (Z=75, Rhenium) | 7.8335 | eV | |
| Os (Z=76, Osmium) | 8.4382 | eV | |
| Ir (Z=77, Iridium) | 8.9670 | eV | |
| Pt (Z=78, Platinum) | 8.9587 | eV | |
| Au (Z=79, Gold) | 9.2255 | eV | |
| Hg (Z=80, Mercury) | 10.4375 | eV | |
| Tl (Z=81, Thallium) | 6.1082 | eV | |
| Pb (Z=82, Lead) | 7.4167 | eV | |
| Bi (Z=83, Bismuth) | 7.2856 | eV | |
| Po (Z=84, Polonium) | 8.417 | eV | |
| At (Z=85, Astatine) | ~9.3 | eV | theory |
| Rn (Z=86, Radon) | 10.7485 | eV | |
| Fr (Z=87, Francium) | 4.0727 | eV | |
| Ra (Z=88, Radium) | 5.2784 | eV | |
| Ac (Z=89, Actinium) | 5.17 | eV | |
| Th (Z=90, Thorium) | 6.3067 | eV | |
| Pa (Z=91, Protactinium) | 5.89 | eV | |
| U (Z=92, Uranium) | 6.1941 | eV | |
| Np (Z=93, Neptunium) | 6.2657 | eV | |
| Pu (Z=94, Plutonium) | 6.0260 | eV | |
| Am (Z=95, Americium) | 5.9738 | eV | |
| Cm (Z=96, Curium) | 5.9915 | eV | |
| Bk (Z=97, Berkelium) | 6.1979 | eV | |
| Cf (Z=98, Californium) | 6.2817 | eV | |
| Es (Z=99, Einsteinium) | 6.3676 | eV | |
| Fm (Z=100, Fermium) | 6.50 | eV | |
| Md (Z=101, Mendelevium) | 6.58 | eV | |
| No (Z=102, Nobelium) | 6.65 | eV | |
| Lr (Z=103, Lawrencium) | 4.9 | eV | |
| Rf (Z=104, Rutherfordium) | ~6.0 | eV | theory |
| Db (Z=105, Dubnium) | ~6.8 | eV | theory |
| Sg (Z=106, Seaborgium) | ~7.8 | eV | theory |
| Bh (Z=107, Bohrium) | ~7.7 | eV | theory |
| Hs (Z=108, Hassium) | ~7.6 | eV | theory |
| Mt (Z=109, Meitnerium) | ~8.7 | eV | theory |
| Ds (Z=110, Darmstadtium) | ~9.2 | eV | theory |
| Rg (Z=111, Roentgenium) | ~10.6 | eV | theory |
| Cn (Z=112, Copernicium) | ~11.97 | eV | theory |
| Nh (Z=113, Nihonium) | ~7.3 | eV | theory |
| Fl (Z=114, Flerovium) | ~8.5 | eV | theory |
| Mc (Z=115, Moscovium) | ~5.6 | eV | theory |
| Lv (Z=116, Livermorium) | ~7.7 | eV | theory |
| Ts (Z=117, Tennessine) | ~7.7 | eV | theory |
| Og (Z=118, Oganesson) | ~8.7 | eV | theory |
Electron Affinities — Selected Elements
Electron Affinity EA
| H (Z=1, Hydrogen) | 0.7542 | eV | |
| Li (Z=3, Lithium) | 0.6180 | eV | |
| B (Z=5, Boron) | 0.2799 | eV | |
| C (Z=6, Carbon) | 1.2621 | eV | |
| O (Z=8, Oxygen) | 1.4611 | eV | |
| F (Z=9, Fluorine) | 3.3988 | eV | |
| Na (Z=11, Sodium) | 0.5479 | eV | |
| Si (Z=14, Silicon) | 1.3895 | eV | |
| P (Z=15, Phosphorus) | 0.7465 | eV | |
| S (Z=16, Sulfur) | 2.0771 | eV | |
| Cl (Z=17, Chlorine) | 3.6127 | eV | |
| K (Z=19, Potassium) | 0.5015 | eV | |
| Se (Z=34, Selenium) | 2.0207 | eV | |
| Br (Z=35, Bromine) | 3.3636 | eV | |
| I (Z=53, Iodine) | 3.0590 | eV | |
| Au (Z=79, Gold) | 2.3086 | eV | |
| At (Z=85, Astatine) | 2.41 ± 0.07 | eV |
Electron Affinity EA (negative — no stable anion)
| He (Z=2) | < 0 | eV | |
| N (Z=7) | < 0 | eV | |
| Ne (Z=10) | < 0 | eV | |
| Ar (Z=18) | < 0 | eV |
Covalent Radii — All Elements
Covalent Radius (single bond, Alvarez 2008)
| H (Z=1) | 31 ± 5 | pm | |
| He (Z=2) | 28 | pm | |
| Li (Z=3) | 128 ± 7 | pm | |
| Be (Z=4) | 96 ± 3 | pm | |
| B (Z=5) | 84 ± 3 | pm | |
| C (Z=6) | 77 ± 1 | pm | |
| N (Z=7) | 71 ± 1 | pm | |
| O (Z=8) | 66 ± 2 | pm | |
| F (Z=9) | 57 ± 3 | pm | |
| Ne (Z=10) | 58 | pm | |
| Na (Z=11) | 166 ± 9 | pm | |
| Mg (Z=12) | 141 ± 7 | pm | |
| Al (Z=13) | 121 ± 4 | pm | |
| Si (Z=14) | 111 ± 2 | pm | |
| P (Z=15) | 107 ± 3 | pm | |
| S (Z=16) | 105 ± 3 | pm | |
| Cl (Z=17) | 102 ± 4 | pm | |
| Ar (Z=18) | 106 ± 10 | pm | |
| K (Z=19) | 203 ± 12 | pm | |
| Ca (Z=20) | 176 ± 10 | pm | |
| Sc (Z=21) | 170 ± 7 | pm | |
| Ti (Z=22) | 160 ± 8 | pm | |
| V (Z=23) | 153 ± 8 | pm | |
| Cr (Z=24) | 139 ± 5 | pm | |
| Mn (Z=25) | 161 ± 8 | pm | |
| Fe (Z=26) | 132 ± 3 | pm | |
| Co (Z=27) | 126 ± 3 | pm | |
| Ni (Z=28) | 124 ± 4 | pm | |
| Cu (Z=29) | 132 ± 4 | pm | |
| Zn (Z=30) | 122 ± 4 | pm | |
| Ga (Z=31) | 122 ± 3 | pm | |
| Ge (Z=32) | 120 ± 4 | pm | |
| As (Z=33) | 119 ± 4 | pm | |
| Se (Z=34) | 120 ± 4 | pm | |
| Br (Z=35) | 114 ± 4 | pm | |
| Kr (Z=36) | 116 ± 4 | pm | |
| Rb (Z=37) | 220 ± 9 | pm | |
| Sr (Z=38) | 195 ± 10 | pm | |
| Y (Z=39) | 190 ± 7 | pm | |
| Zr (Z=40) | 175 ± 7 | pm | |
| Nb (Z=41) | 164 ± 6 | pm | |
| Mo (Z=42) | 154 ± 5 | pm | |
| Tc (Z=43) | 147 ± 7 | pm | |
| Ru (Z=44) | 146 ± 7 | pm | |
| Rh (Z=45) | 142 ± 7 | pm | |
| Pd (Z=46) | 139 ± 6 | pm | |
| Ag (Z=47) | 145 ± 5 | pm | |
| Cd (Z=48) | 144 ± 9 | pm | |
| In (Z=49) | 142 ± 5 | pm | |
| Sn (Z=50) | 139 ± 4 | pm | |
| Sb (Z=51) | 139 ± 5 | pm | |
| Te (Z=52) | 138 ± 4 | pm | |
| I (Z=53) | 139 ± 3 | pm | |
| Xe (Z=54) | 140 ± 9 | pm | |
| Cs (Z=55) | 244 ± 11 | pm | |
| Ba (Z=56) | 215 ± 11 | pm | |
| La (Z=57) | 207 ± 8 | pm | |
| Hf (Z=72) | 175 ± 10 | pm | |
| Ta (Z=73) | 170 ± 8 | pm | |
| W (Z=74) | 162 ± 7 | pm | |
| Re (Z=75) | 151 ± 7 | pm | |
| Os (Z=76) | 144 ± 4 | pm | |
| Ir (Z=77) | 141 ± 6 | pm | |
| Pt (Z=78) | 136 ± 5 | pm | |
| Au (Z=79) | 136 ± 6 | pm | |
| Hg (Z=80) | 132 ± 5 | pm | |
| Tl (Z=81) | 145 ± 7 | pm | |
| Pb (Z=82) | 146 ± 5 | pm | |
| Bi (Z=83) | 148 ± 4 | pm | |
| Po (Z=84) | 140 ± 4 | pm | |
| At (Z=85) | 150 | pm |
Selected Isotope Atomic Masses (AME 2020)
¹H (Hydrogen-1, Protium)
| Atomic mass | 1.007 825 032 23 ± 0.000 000 000 09 | u |
²H (Hydrogen-2, Deuterium)
| Atomic mass | 2.014 101 778 12 ± 0.000 000 000 04 | u |
³H (Hydrogen-3, Tritium)
| Atomic mass | 3.016 049 281 0 ± 0.000 000 000 8 | u |
³He (Helium-3)
| Atomic mass | 3.016 029 322 0 ± 0.000 000 001 1 | u |
⁴He (Helium-4, alpha particle)
| Atomic mass | 4.002 603 254 13 ± 0.000 000 000 06 | u |
⁶Li (Lithium-6)
| Atomic mass | 6.015 122 887 ± 0.000 000 010 | u |
⁷Li (Lithium-7)
| Atomic mass | 7.016 003 434 ± 0.000 000 008 | u |
¹²C (Carbon-12)
| Atomic mass | 12.000 000 000 | u | exact |
¹³C (Carbon-13)
| Atomic mass | 13.003 354 835 ± 0.000 000 002 | u |
¹⁴C (Carbon-14)
| Atomic mass | 14.003 241 988 ± 0.000 000 004 | u |
¹⁴N (Nitrogen-14)
| Atomic mass | 14.003 074 004 ± 0.000 000 002 | u |
¹⁶O (Oxygen-16)
| Atomic mass | 15.994 914 620 ± 0.000 000 001 | u |
¹⁸O (Oxygen-18)
| Atomic mass | 17.999 159 613 ± 0.000 000 003 | u |
²³Na (Sodium-23)
| Atomic mass | 22.989 769 28 ± 0.000 000 02 | u |
²⁴Mg (Magnesium-24)
| Atomic mass | 23.985 041 70 ± 0.000 000 09 | u |
²⁷Al (Aluminium-27)
| Atomic mass | 26.981 538 53 ± 0.000 000 02 | u |
²⁸Si (Silicon-28)
| Atomic mass | 27.976 926 534 ± 0.000 000 006 | u |
³²S (Sulfur-32)
| Atomic mass | 31.972 071 174 ± 0.000 000 014 | u |
³⁵Cl (Chlorine-35)
| Atomic mass | 34.968 852 682 ± 0.000 000 004 | u |
⁴⁰Ar (Argon-40)
| Atomic mass | 39.962 383 124 ± 0.000 000 003 | u |
⁴⁰Ca (Calcium-40)
| Atomic mass | 39.962 590 866 ± 0.000 000 022 | u |
⁵⁶Fe (Iron-56)
| Atomic mass | 55.934 937 63 ± 0.000 000 03 | u |
⁵⁸Ni (Nickel-58)
| Atomic mass | 57.935 342 9 ± 0.000 000 7 | u |
⁶³Cu (Copper-63)
| Atomic mass | 62.929 597 46 ± 0.000 000 04 | u |
⁸⁴Kr (Krypton-84)
| Atomic mass | 83.911 506 4 ± 0.000 000 4 | u |
¹⁰⁷Ag (Silver-107)
| Atomic mass | 106.905 091 6 ± 0.000 000 4 | u |
¹³²Xe (Xenon-132)
| Atomic mass | 131.904 154 6 ± 0.000 000 4 | u |
¹³³Cs (Caesium-133)
| Atomic mass | 132.905 451 96 ± 0.000 000 07 | u |
¹⁹⁷Au (Gold-197)
| Atomic mass | 196.966 570 1 ± 0.000 000 6 | u |
²⁰⁸Pb (Lead-208)
| Atomic mass | 207.976 652 1 ± 0.000 001 3 | u |
²³²Th (Thorium-232)
| Atomic mass | 232.038 055 8 ± 0.000 001 9 | u |
²³⁵U (Uranium-235)
| Atomic mass | 235.043 929 9 ± 0.000 001 9 | u |
²³⁸U (Uranium-238)
| Atomic mass | 238.050 788 2 ± 0.000 001 8 | u |
²³⁹Pu (Plutonium-239)
| Atomic mass | 239.052 163 6 ± 0.000 001 9 | u |
Nuclear Spins & Magnetic Moments
¹H (Proton)
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +2.792 847 344 62 ± 0.000 000 000 82 | μN |
²H (Deuteron)
| Spin I | 1 | exact | |
| Magnetic moment μ | +0.857 438 231 ± 0.000 000 009 | μN | |
| Electric quadrupole moment Q | +2.860 ± 0.015 | mfm² |
³H (Triton)
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +2.978 962 460 ± 0.000 000 014 | μN |
³He
| Spin I | 1/2 | exact | |
| Magnetic moment μ | −2.127 625 307 ± 0.000 000 025 | μN |
⁴He
| Spin I | 0 | exact |
⁶Li
| Spin I | 1 | exact | |
| Magnetic moment μ | +0.822 047 ± 0.000 003 | μN |
⁷Li
| Spin I | 3/2 | exact | |
| Magnetic moment μ | +3.256 427 ± 0.000 002 | μN |
¹²C
| Spin I | 0 | exact |
¹³C
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +0.702 411 6 ± 0.000 001 3 | μN |
¹⁴N
| Spin I | 1 | exact | |
| Magnetic moment μ | +0.403 761 ± 0.000 002 | μN |
¹⁶O
| Spin I | 0 | exact |
¹⁷O
| Spin I | 5/2 | exact | |
| Magnetic moment μ | −1.893 79 ± 0.000 09 | μN |
¹⁹F
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +2.628 868 ± 0.000 008 | μN |
²³Na
| Spin I | 3/2 | exact | |
| Magnetic moment μ | +2.217 520 ± 0.000 020 | μN |
²⁷Al
| Spin I | 5/2 | exact | |
| Magnetic moment μ | +3.641 507 ± 0.000 021 | μN |
²⁹Si
| Spin I | 1/2 | exact | |
| Magnetic moment μ | −0.555 29 ± 0.000 03 | μN |
³¹P
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +1.131 60 ± 0.000 03 | μN |
³⁵Cl
| Spin I | 3/2 | exact | |
| Magnetic moment μ | +0.821 87 ± 0.000 03 | μN |
³⁹K
| Spin I | 3/2 | exact | |
| Magnetic moment μ | +0.391 470 ± 0.000 003 | μN |
⁴⁰K
| Spin I | 4 | exact | |
| Magnetic moment μ | −1.298 10 ± 0.000 03 | μN |
⁵⁷Fe
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +0.090 623 ± 0.000 009 | μN |
⁵⁹Co
| Spin I | 7/2 | exact | |
| Magnetic moment μ | +4.627 ± 0.009 | μN |
⁶³Cu
| Spin I | 3/2 | exact | |
| Magnetic moment μ | +2.227 34 ± 0.000 06 | μN |
⁸⁷Rb
| Spin I | 3/2 | exact | |
| Magnetic moment μ | +2.751 818 ± 0.000 002 | μN |
¹³³Cs
| Spin I | 7/2 | exact | |
| Magnetic moment μ | +2.582 025 ± 0.000 003 | μN |
²⁰⁷Pb
| Spin I | 1/2 | exact | |
| Magnetic moment μ | +0.592 583 ± 0.000 009 | μN |
Nuclear Binding Energies per Nucleon
²H (A=2)
| BE / A | 1.1123 | MeV/nucleon |
³He (A=3)
| BE / A | 2.5727 | MeV/nucleon |
⁴He (A=4) — α particle
| BE / A | 7.0739 | MeV/nucleon | |
| Total BE | 28.296 | MeV |
⁶Li (A=6)
| BE / A | 5.3324 | MeV/nucleon |
⁷Li (A=7)
| BE / A | 5.6063 | MeV/nucleon |
¹²C (A=12)
| BE / A | 7.6801 | MeV/nucleon |
¹⁶O (A=16)
| BE / A | 7.9762 | MeV/nucleon |
²⁰Ne (A=20)
| BE / A | 8.0319 | MeV/nucleon |
²⁴Mg (A=24)
| BE / A | 8.2607 | MeV/nucleon |
²⁸Si (A=28)
| BE / A | 8.4479 | MeV/nucleon |
³²S (A=32)
| BE / A | 8.4931 | MeV/nucleon |
⁴⁰Ca (A=40)
| BE / A | 8.5513 | MeV/nucleon |
⁵⁶Fe (A=56) — near peak
| BE / A | 8.7905 | MeV/nucleon |
⁵⁸Ni (A=58) — binding energy peak
| BE / A | 8.7946 | MeV/nucleon |
⁶³Cu (A=63)
| BE / A | 8.7517 | MeV/nucleon |
⁸⁴Kr (A=84)
| BE / A | 8.7217 | MeV/nucleon |
¹²⁰Sn (A=120)
| BE / A | 8.5046 | MeV/nucleon |
¹⁹⁷Au (A=197)
| BE / A | 7.9161 | MeV/nucleon |
²⁰⁸Pb (A=208) — doubly magic
| BE / A | 7.8675 | MeV/nucleon |
²³⁵U (A=235)
| BE / A | 7.5907 | MeV/nucleon |
²³⁸U (A=238)
| BE / A | 7.5701 | MeV/nucleon |
Radioactive Half-Lives
³H (Tritium)
| Half-life | 12.312 ± 0.025 | yr | |
| Decay mode | β⁻ → ³He + e⁻ + ν̄e |
¹⁴C (Carbon-14)
| Half-life | 5 700 ± 30 | yr | |
| Decay mode | β⁻ → ¹⁴N | ||
| Application | Radiocarbon dating |
²²Na (Sodium-22)
| Half-life | 2.6019 ± 0.0004 | yr | |
| Decay mode | β⁺ (90%) + EC; produces 511 keV annihilation γ |
³²P (Phosphorus-32)
| Half-life | 14.268 ± 0.005 | days | |
| Decay mode | β⁻ → ³²S |
³⁵S (Sulfur-35)
| Half-life | 87.37 ± 0.04 | days |
⁴⁰K (Potassium-40)
| Half-life | 1.248 × 10⁹ ± 0.003 × 10⁹ | yr | |
| Decay mode | β⁻ (89%) to ⁴⁰Ca; EC (11%) to ⁴⁰Ar + 1.46 MeV γ |
⁶⁰Co (Cobalt-60)
| Half-life | 5.2714 ± 0.0005 | yr | |
| γ energies | 1.173 MeV + 1.332 MeV |
⁹⁰Sr (Strontium-90)
| Half-life | 28.8 ± 0.2 | yr | |
| Decay mode | β⁻ → ⁹⁰Y (t½ = 64.0 h) → ⁹⁰Zr |
¹³¹I (Iodine-131)
| Half-life | 8.0252 ± 0.0006 | days | |
| Decay mode | β⁻; principal γ 364 keV |
¹³⁷Cs (Caesium-137)
| Half-life | 30.07 ± 0.08 | yr | |
| γ energy | 661.7 keV |
²²⁶Ra (Radium-226)
| Half-life | 1 600 ± 7 | yr | |
| Decay mode | α → ²²²Rn + 4.871 MeV |
²³²Th (Thorium-232)
| Half-life | 1.405 × 10¹⁰ ± 0.006 × 10¹⁰ | yr |
²³⁵U (Uranium-235)
| Half-life | 7.038 × 10⁸ ± 0.005 × 10⁸ | yr | |
| Decay mode | α → ²³¹Th |
²³⁸U (Uranium-238)
| Half-life | 4.468 × 10⁹ ± 0.003 × 10⁹ | yr | |
| Decay mode | α → ²³⁴Th |
²³⁷Np (Neptunium-237)
| Half-life | 2.144 × 10⁶ ± 0.007 × 10⁶ | yr |
²³⁹Pu (Plutonium-239)
| Half-life | 24 110 ± 30 | yr | |
| Decay mode | α → ²³⁵U + 5.244 MeV |
²⁴¹Am (Americium-241)
| Half-life | 432.7 ± 0.6 | yr | |
| γ energy | 59.54 keV (smoke detectors) |
Nuclear Reactions & Q-Values
D + T fusion
| Reaction | ²H + ³H → ⁴He + n | ||
| Q-value | +17.589 | MeV | |
| Product energies | n: 14.1 MeV; ⁴He: 3.5 MeV |
D + D fusion (branch 1)
| Reaction | ²H + ²H → ³He + n | ||
| Q-value | +3.269 | MeV |
D + D fusion (branch 2)
| Reaction | ²H + ²H → ³H + p | ||
| Q-value | +4.033 | MeV |
D + ³He fusion
| Reaction | ²H + ³He → ⁴He + p | ||
| Q-value | +18.354 | MeV |
pp-I chain step 1
| Reaction | p + p → ²H + e⁺ + νe | ||
| Q-value | +1.442 | MeV |
pp-I chain step 2
| Reaction | ²H + p → ³He + γ | ||
| Q-value | +5.494 | MeV |
pp-I chain step 3
| Reaction | ³He + ³He → ⁴He + 2p | ||
| Q-value | +12.860 | MeV |
pp chain net reaction
| Reaction | 4p → ⁴He + 2e⁺ + 2νe + 2γ | ||
| Energy released | 26.73 | MeV |
Thermal neutron fission of ²³⁵U
| Reaction (typical) | n + ²³⁵U → ²³⁶U* → fission products + 2–3n | ||
| Energy released (total) | ~202 | MeV | |
| Prompt energy (kinetic + γ) | ~169 | MeV | |
| Avg. neutrons per fission ν̄ | 2.436 ± 0.005 | ||
| Thermal cross section σf | 585.1 ± 1.0 | b |
Neutron capture ²³⁸U
| Reaction | n + ²³⁸U → ²³⁹U → ²³⁹Np → ²³⁹Pu |
Alpha decay ²²⁶Ra
| Reaction | ²²⁶Ra → ²²²Rn + α | ||
| Q-value | +4.871 | MeV |
Neutron β⁻ decay
| Reaction | n → p + e⁻ + ν̄e | ||
| Q-value | +0.782 | MeV | |
| Mean lifetime τ | 878.4 ± 0.5 | s |