![](//upload.wikimedia.org/wikipedia/commons/thumb/2/27/Na_%28Sodium%29.jpg/220px-Na_%28Sodium%29.jpg) |
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Appearance | silvery white metallic |
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| 22.98976928(2)[1] |
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Group | group 1: hydrogen and alkali metals |
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Period | period 3 |
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Block | s-block |
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Electron configuration | [Ne] 3s1 |
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Electrons per shell | 2, 8, 1 |
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Phase at STP | solid |
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Melting point | 370.944 K (97.794 °C, 208.029 °F) |
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Boiling point | 1156.090 K (882.940 °C, 1621.292 °F) |
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Density (near r.t.) | 0.968 g/cm3 |
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when liquid (at m.p.) | 0.927 g/cm3 |
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Critical point | 2573 K, 35 MPa (extrapolated) |
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Heat of fusion | 2.60 kJ/mol |
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Heat of vaporization | 97.42 kJ/mol |
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Molar heat capacity | 28.230 J/(mol·K) |
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Vapor pressure
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
554 |
617 |
697 |
802 |
946 |
1153 |
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Oxidation states | −1, 0,[2] +1 (a strongly basic oxide) |
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Electronegativity | Pauling scale: 0.93 |
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Ionization energies | - 1st: 495.8 kJ/mol
- 2nd: 4562 kJ/mol
- 3rd: 6910.3 kJ/mol
- (more)
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Atomic radius | empirical: 186 pm |
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Covalent radius | 166±9 pm |
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Van der Waals radius | 227 pm |
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Spectral lines of sodium |
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Natural occurrence | primordial |
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Crystal structure | body-centered cubic (bcc) |
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Speed of sound thin rod | 3200 m/s (at 20 °C) |
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Thermal expansion | 71 µm/(m⋅K) (at 25 °C) |
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Thermal conductivity | 142 W/(m⋅K) |
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Electrical resistivity | 47.7 nΩ⋅m (at 20 °C) |
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Magnetic ordering | paramagnetic[3] |
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Molar magnetic susceptibility | +16.0·10−6 cm3/mol (298 K)[4] |
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Young's modulus | 10 GPa |
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Shear modulus | 3.3 GPa |
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Bulk modulus | 6.3 GPa |
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Mohs hardness | 0.5 |
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Brinell hardness | 0.69 MPa |
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CAS Number | 7440-23-5 |
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Discovery and first isolation | Humphry Davy (1807) |
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Symbol | "Na": from New Latin natrium, coined from German Natron, 'natron' |
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Category: Sodium | references |