|
|
| Atomic properties |
|---|
| Atomic number |
8 |
|---|
| Standard atomic weight |
15.9994(3) |
|---|
| Electron configuration |
[He] 2s2 2p4 |
|---|
| Physical properties (O2)[1] |
|---|
| Melting point |
54.8(2) K (−218.8 °C) |
|---|
| Boiling point |
90.2(2) K (−183.0 °C) |
|---|
| Critical point |
154.58 K, 50.43 bar |
|---|
| Chemical properties[2] |
|---|
| Electronegativity |
3.44 (Pauling) |
|---|
| Ionization energies[3][4] |
|---|
| 1st |
13.618 06 eV,
1313.943 kJ mol−1 |
|---|
| 2nd |
35.1211 eV,
3388.67 kJ mol−1 |
|---|
| 3rd |
54.9355 eV,
5300.47 kJ mol−1 |
|---|
| 4th |
77.4135 eV,
7469.27 kJ mol−1 |
|---|
| 5th |
113.8989 eV,
10 989.57 kJ mol−1 |
|---|
| 6th |
138.1196 eV,
13 326.52 kJ mol−1 |
|---|
| 7th |
739.3268 eV,
71 334.20 kJ mol−1 |
|---|
| 8th |
871.4097 eV,
84 078.26 kJ mol−1 |
|---|
| Total |
2043.8432 eV,
197 200.9 kJ mol−1 |
|---|
| Electron affinity[3] |
|---|
| 140.9759(42) kJ mol−1 | | Atomic radii |
|---|
| Covalent radius |
66 pm |
|---|
| Van der Waals radius |
152 pm |
|---|
| Thermodynamic properties (O2)[1][5] |
|---|
| Standard entropy |
205.152(5) J K−1 mol−1 |
|---|
| Enthalpy change of atomization |
249.18(10) kJ mol−1 |
|---|
| Entropy change of atomization |
−44.093(6) J K−1 mol−1 |
|---|
| Enthalpy change of fusion |
0.444 kJ mol−1 |
|---|
| Enthalpy change of vaporization |
6.82 kJ mol−1 |
|---|
| Molar heat capacity (Cp) |
29.378 J K−1 mol−1 |
|---|
| Miscellaneous |
|---|
| CAS number |
7782-44-7 (O2)
17778-80-2 (atomic) |
|---|
| EC number |
231-956-9 |
|---|
| Where appropriate, and unless otherwise stated, data are given for 100 kPa (1 bar) and 298.15 K (25 °C). | |
|
Oxygen (ˈɒksɨdʒɨn) is a colourless gas which makes up about one fifth of the Earth's atmosphere. Its name comes from the Greek ὀξύς (oxys; acid, literally "sharp", from the taste of acids) and -γενής (-genēs; producer, literally "begetter").
References
- ↑ 1.0 1.1 Oxygen. In NIST Chemistry WebBook; National Institute for Standards and Technology, <http://webbook.nist.gov/cgi/inchi/InChI%3D1S/O2/c1-2>. (accessed 15 March 2010).
- ↑ Allred, A. L. Electronegativity values from thermochemical data. J. Inorg. Nucl. Chem. 1961, 17 (3–4), 215–21. DOI: 10.1016/0022-1902(61)80142-5.
- ↑ 3.0 3.1 Oxygen, atomic. In NIST Chemistry WebBook; National Institute for Standards and Technology, <http://webbook.nist.gov/cgi/inchi/InChI%3D1S/O>. (accessed 15 March 2010).
- ↑ Mohr, Peter J.; Taylor, Barry N. CODATA recommended values of the fundamental physical constants: 2002. Rev. Mod. Phys. 2005, 77 (1), 1–107. DOI: 10.1103/RevModPhys.77.1.
- ↑ Cox, J. D.; Wagman, D. D.; Medvedev, V. A. CODATA Key Values for Thermodynamics; Hemisphere: New York, 1989. ISBN 0891167587, <http://www.codata.org/resources/databases/key1.html>.
External links
