| Atomic Number | 19 | 
|---|---|
| Atomic Weight | 39.0983 | 
| mass number | 39 | 
| Group | 1 | 
|---|---|
| Period | 4 | 
| Block | s | 
| proton | 19 p+ | 
|---|---|
| neutron | 20 n0 | 
| electron | 19 e- | 
| Atomic Radius | |
|---|---|
| molar volume | |
| Covalent Radius | |
| Metallic Radius | |
| ionic radius | |
| Crystal Radius | |
| Van der Waals radius | |
| density | 
| energy | |
|---|---|
| proton affinity | |
| electron affinity | |
| ionization energy | |
| enthalpy of vaporization | |
| enthalpy of fusion | |
| standard enthalpy of formation | |
| electron | |
| electron shell | 2, 8, 8, 1 | 
| valence electron | 1 ⓘ | 
| electron configuration | [Ar] 4s1ⓘ 1s2 2s2 2p6 3s2 3p6 4s1 | 
| oxidation number | -1, 1 | 
| electronegativity | 0.82 | 
| Electrophilicity Index | |
| fundamental state of matter | |
| phase of matter{ERROR} | |
| gaseous state of matter | |
| Boiling Point | |
| Melting Point | |
| critical pressure | |
| critical temperature | |
| triple point | |
| appearance | |
| color | Black | 
| appearance | silvery gray | 
| refractive index | |
| thermodynamic material property | |
| Thermal Conductivity | |
| thermal expansion | |
| molar heat capacity | |
| Specific Heat Capacity | |
| heat capacity ratio | |
| electrical properties | |
| type | Conductor | 
| electrical conductivity | |
| electrical resistivity | |
| superconductivity | |
| magnetism | |
| type | paramagnetic | 
| magnetic susceptibility (Mass) | 0.0000000067 m³/Kg | 
| magnetic susceptibility (Molar) | 0.000000000262 m³/mol | 
| magnetic susceptibility (Volume) | 0.00000574  | 
| magnetic ordering | |
| Curie temperature | |
| Néel temperature | |
| structure | |
| Crystal Structure | {ERROR} | 
| lattice constant | |
| Lattice Angles | π/2, π/2, π/2 | 
| mechanical property | |
| hardness | |
| bulk modulus | |
| shear modulus | |
| Young's modulus | |
| Poisson's ratio | |
| speed of sound | |
| classification | |
| Category | Actinides, Alkali metals | 
| CAS Group | IA | 
| IUPAC Group | IA | 
| Glawe Number | 10 | 
| Mendeleev Number | 3 | 
| Pettifor Number | 10 | 
| Geochemical Class | alkali metal | 
| Goldschmidt classification | litophile | 
| Gas Basicity | |
|---|---|
| polarizability | |
| C6 Dispersion Coefficient | |
| allotrope | |
| Neutron cross section | 2.1  | 
| Neutron Mass Absorption | 0.0018  | 
| quantum number | 2S1/2 | 
| space group | 229 (Im_3m) | 
| Stable Isotopes | 2 | 
|---|---|
| Unstable Isotopes | 27 | 
| Natural Isotopes | 3 | 
| mass number | 31 | 
|---|---|
| neutron number | 12 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 2019 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| 3p | 100% | 
| mass number | 32 | 
|---|---|
| neutron number | 13 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 1 | 
| nuclear quadrupole moment | |
| time of discovery or invention | |
| parity | + | 
| decay mode | intensity | 
|---|---|
| p (proton emission) | 
| mass number | 33 | 
|---|---|
| neutron number | 14 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | |
| parity | + | 
| decay mode | intensity | 
|---|---|
| p (proton emission) | 
| mass number | 34 | 
|---|---|
| neutron number | 15 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 1 | 
| nuclear quadrupole moment | |
| time of discovery or invention | |
| parity | + | 
| decay mode | intensity | 
|---|---|
| p (proton emission) | 
| mass number | 35 | 
|---|---|
| neutron number | 16 | 
| Relative Atomic Mass | |
| g-factor | 0.26133333333333 ± 0.0046666666666667  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 175.2 ± 1.9 ms | 
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1976 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| β+ p (β+-delayed proton emission) | 0.37% | 
| mass number | 36 | 
|---|---|
| neutron number | 17 | 
| Relative Atomic Mass | |
| g-factor | 0.274 ± 0.0005  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 341 ± 3 ms | 
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1967 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| β+ p (β+-delayed proton emission) | 0.048% | 
| β+α (β+-delayed α emission) | 0.0034% | 
| mass number | 37 | 
|---|---|
| neutron number | 18 | 
| Relative Atomic Mass | |
| g-factor | 0.13547333333333 ± 0.00004  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 1.23651 ± 0.00094 s | 
| spin | 3/2 | 
| nuclear quadrupole moment | 0.109 ± 0.004  | 
| time of discovery or invention | 1958 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| mass number | 38 | 
|---|---|
| neutron number | 19 | 
| Relative Atomic Mass | |
| g-factor | 0.457 ± 0.002  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 7.651 ± 0.019 m | 
| spin | 3 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1937 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| mass number | 39 | 
|---|---|
| neutron number | 20 | 
| Relative Atomic Mass | |
| g-factor | 0.26098 ± 0.0000053333333333333  | 
| natural abundance | 93.2581 ± 0.0044  | 
| radioactivity | stable isotope | 
| half-life | Not Radioactive ☢️ | 
| spin | 3/2 | 
| nuclear quadrupole moment | 0.0603 ± 0.0006  | 
| time of discovery or invention | 1921 | 
| parity | + | 
| mass number | 40 | 
|---|---|
| neutron number | 21 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | 0.0117 ± 0.0001  | 
| radioactivity | ☢️ radioactive element | 
| half-life | 1.248 ± 0.003 Gy | 
| spin | 4 | 
| nuclear quadrupole moment | -0.075 ± 0.0008  | 
| time of discovery or invention | 1935 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 89.28% | 
| β+ (β+ decay; β+ = ϵ + e+) | 10.72% | 
| mass number | 41 | 
|---|---|
| neutron number | 22 | 
| Relative Atomic Mass | |
| g-factor | 0.143248 ± 0.0000033333333333333  | 
| natural abundance | 6.7302 ± 0.0044  | 
| radioactivity | stable isotope | 
| half-life | Not Radioactive ☢️ | 
| spin | 3/2 | 
| nuclear quadrupole moment | 0.0734 ± 0.0007  | 
| time of discovery or invention | 1921 | 
| parity | + | 
| mass number | 42 | 
|---|---|
| neutron number | 23 | 
| Relative Atomic Mass | |
| g-factor | -0.57125 ± 0.0003  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 12.355 ± 0.007 h | 
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1935 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| mass number | 43 | 
|---|---|
| neutron number | 24 | 
| Relative Atomic Mass | |
| g-factor | 0.10886666666667 ± 0.00053333333333333  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 22.3 ± 0.1 h | 
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1949 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| mass number | 44 | 
|---|---|
| neutron number | 25 | 
| Relative Atomic Mass | |
| g-factor | -0.428 ± 0.002  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 22.13 ± 0.19 m | 
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1954 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| mass number | 45 | 
|---|---|
| neutron number | 26 | 
| Relative Atomic Mass | |
| g-factor | 0.1156 ± 0.00053333333333333  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 17.8 ± 0.6 m | 
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1964 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| mass number | 46 | 
|---|---|
| neutron number | 27 | 
| Relative Atomic Mass | |
| g-factor | -0.5255 ± 0.003  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 96.3 ± 0.08 s | 
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1965 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| mass number | 47 | 
|---|---|
| neutron number | 28 | 
| Relative Atomic Mass | |
| g-factor | 3.866 ± 0.018  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 17.38 ± 0.03 s | 
| spin | 1/2 | 
| nuclear quadrupole moment | 0  | 
| time of discovery or invention | 1964 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| mass number | 48 | 
|---|---|
| neutron number | 29 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 6.83 ± 0.14 s | 
| spin | 1 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1972 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | 1.14% | 
| mass number | 49 | 
|---|---|
| neutron number | 30 | 
| Relative Atomic Mass | |
| g-factor | 2.6772 ± 0.0016  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 1.26 ± 0.05 s | 
| spin | 1/2 | 
| nuclear quadrupole moment | 0  | 
| time of discovery or invention | 1972 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | 86% | 
| mass number | 50 | 
|---|---|
| neutron number | 31 | 
| Relative Atomic Mass | |
| g-factor | 0  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 472 ± 4 ms | 
| spin | 0 | 
| nuclear quadrupole moment | 0  | 
| time of discovery or invention | 1972 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | 28.6% | 
| 2n (2-neutron emission) | 
| mass number | 51 | 
|---|---|
| neutron number | 32 | 
| Relative Atomic Mass | |
| g-factor | 0.342 ± 0.0013333333333333  | 
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 365 ± 5 ms | 
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1983 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | 65% | 
| 2n (2-neutron emission) | 
| mass number | 52 | 
|---|---|
| neutron number | 33 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 110 ± 4 ms | 
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1983 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | 72.2% | 
| 2n (2-neutron emission) | 2.3% | 
| mass number | 53 | 
|---|---|
| neutron number | 34 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 30 ± 5 ms | 
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1983 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | 64% | 
| 2n (2-neutron emission) | 10% | 
| mass number | 54 | 
|---|---|
| neutron number | 35 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | 10 ± 5 ms | 
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 1983 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | 100% | 
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) | 
| mass number | 55 | 
|---|---|
| neutron number | 36 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 2009 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | |
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) | 
| mass number | 56 | 
|---|---|
| neutron number | 37 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 2009 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | |
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) | 
| mass number | 57 | 
|---|---|
| neutron number | 38 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 2018 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | |
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) | 
| mass number | 58 | 
|---|---|
| neutron number | 39 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 2019 | 
| parity | - | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | |
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) | 
| mass number | 59 | 
|---|---|
| neutron number | 40 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioactivity | ☢️ radioactive element | 
| half-life | |
| spin | 3/2 | 
| nuclear quadrupole moment | |
| time of discovery or invention | 2018 | 
| parity | + | 
| decay mode | intensity | 
|---|---|
| β− (β− decay) | |
| β− n (β−-delayed neutron emission) | |
| 2n (2-neutron emission) | 

| discoverer or inventor | Sir Humphrey Davy | 
|---|---|
| location of discovery | England | 
| time of discovery or invention | 1807 | 
| etymology | English: pot ash; symbol from Latin: kalium, (alkali). | 
| pronunciation | pe-TASS-i-em (English) | 
| Abundance | |
|---|---|
| Abundance in Earth's crust | |
| natural abundance (ocean) | |
| natural abundance (Human body) | 0.2 % | 
| natural abundance (meteoroid) | 0.07 % | 
| natural abundance (La) | 0.0004 % | 
| Abundance in Universe | 0.0003 % | 
| 1 | s | 0.5105 | 
| 2 | p | 3.9728 | 
| 2 | s | 5.9938 | 
| 3 | p | 11.2744 | 
| 3 | s | 10.3201 | 
| 4 | s | 15.5048 |