Fe, Cr, O

iron (chemical element) | chromium (chemical element) | oxygen (chemical element)

Periodic table location

Images

| iron | chromium | oxygen atomic symbol | Fe | Cr | O atomic number | 26 | 24 | 8 short electronic configuration | [Ar]4s^23d^6 | [Ar]4s^13d^5 | [He]2s^22p^4 Aufbau diagram | 3d 4s | 3d 4s | 2p 2s block | d | d | p group | 8 | 6 | 16 period | 4 | 4 | 2 atomic mass | 55.845 u | 51.9961 u | 15.999 u half-life | (stable) | (stable) | (stable)

| iron | chromium | oxygen phase at STP | solid | solid | gas melting point | 1538 °C | 1907 °C | -218.3 °C boiling point | 2861 °C | 2671 °C | -182.9 °C critical temperature | (unknown) | | 154.59 K critical pressure | (unknown) | | 5.043 MPa molar heat of fusion | 13.8 kJ/mol | 20.5 kJ/mol | 0.222 kJ/mol molar heat of vaporization | 347 kJ/mol | 339 kJ/mol | 3.41 kJ/mol specific heat at STP | 449 J/(kg K) | 448 J/(kg K) | 919 J/(kg K) adiabatic index | | | 7/5 Néel point | | 393 K | (properties at standard conditions)

| iron | chromium | oxygen density | 7.874 g/cm^3 | 7.19 g/cm^3 | 0.001429 g/cm^3 liquid density | 6.98 g/cm^3 | 6.3 g/cm^3 | molar volume | 7.092 cm^3/mol | 7.232 cm^3/mol | 11200 cm^3/mol Mohs hardness | 4 (≈ fluorite) | 8.5 (between topaz and corundum) | Vickers hardness | 608 MPa | 1060 MPa | Brinell hardness | 490 MPa | 1120 MPa | bulk modulus | 170 GPa | 160 GPa | shear modulus | 82 GPa | 115 GPa | Young's modulus | 211 GPa | 279 GPa | Poisson ratio | 0.29 | 0.21 | tensile yield strength | 50 MPa | | refractive index | (unknown) | | 1.000271 sound speed | 4910 m/s | 5940 m/s | 317.5 m/s thermal expansion | 1.18×10^-5 K^(-1) | 4.9×10^-6 K^(-1) | thermal conductivity | 80 W/(m K) | 94 W/(m K) | 0.02658 W/(m K) (properties at standard conditions)

| iron | chromium | oxygen electrical type | conductor | conductor | resistivity | 9.7×10^-8 Ω m (ohm meters) | 1.3×10^-7 Ω m (ohm meters) | electrical conductivity | 1×10^7 S/m (siemens per meter) | 7.9×10^6 S/m (siemens per meter) | magnetic type | ferromagnetic | antiferromagnetic | paramagnetic volume magnetic susceptibility | | 3.177×10^-4 | 1.90772×10^-6 mass magnetic susceptibility | | 4.45×10^-8 m^3/kg (cubic meters per kilogram) | 1.335×10^-6 m^3/kg (cubic meters per kilogram) molar magnetic susceptibility | | 2.314×10^-9 m^3/mol (cubic meters per mole) | 4.27184×10^-8 m^3/mol (cubic meters per mole) Curie point | 1043 K (kelvins) | | Néel point | | 393 K (kelvins) | work function | (4.67 to 4.81) eV | 4.5 eV (Polycrystalline) | threshold frequency | (1.129×10^15 to 1.163×10^15) Hz (hertz) | 1.088×10^15 Hz (hertz) | color | (gray) | (silver) | (colorless) refractive index | (unknown) | | 1.000271

| iron | chromium | oxygen valence | 3 | 6 | 2 electronegativity | 1.83 | 1.66 | 3.44 electron affinity | 15.7 kJ/mol (kilojoules per mole) | 64.3 kJ/mol (kilojoules per mole) | 141 kJ/mol (kilojoules per mole) first ionization energy | 762.5 kJ/mol (kilojoules per mole) | 652.9 kJ/mol (kilojoules per mole) | 1313.9 kJ/mol (kilojoules per mole) ionization energies | 762.5 kJ/mol | 1561.9 kJ/mol | 2957 kJ/mol | 5290 kJ/mol | 7240 kJ/mol | 9560 kJ/mol | 12060 kJ/mol | 14580 kJ/mol | 22540 kJ/mol | 25290 kJ/mol | 28000 kJ/mol | 31920 kJ/mol | 34830 kJ/mol | 37840 kJ/mol | 44100 kJ/mol | 47206 kJ/mol | 122200 kJ/mol | 131000 kJ/mol | 140500 kJ/mol | 152600 kJ/mol | 163000 kJ/mol | 652.9 kJ/mol | 1590.6 kJ/mol | 2987 kJ/mol | 4743 kJ/mol | 6702 kJ/mol | 8744.9 kJ/mol | 15455 kJ/mol | 17820 kJ/mol | 20190 kJ/mol | 23580 kJ/mol | 26130 kJ/mol | 28750 kJ/mol | 34230 kJ/mol | 37066 kJ/mol | 97510 kJ/mol | 105800 kJ/mol | 114300 kJ/mol | 125300 kJ/mol | 134700 kJ/mol | 144300 kJ/mol | 157700 kJ/mol | 1313.9 kJ/mol | 3388.3 kJ/mol | 5300.5 kJ/mol | 7469.2 kJ/mol | 10989.5 kJ/mol | 13326.5 kJ/mol | 71330 kJ/mol | 84078 kJ/mol

Reactivity

| iron | chromium | oxygen term symbol | ^5D_4 | ^7S_3 | ^3P_2 atomic radius | 140 pm | 140 pm | 60 pm covalent radius | 132 pm | 139 pm | 66 pm van der Waals radius | (unknown) | | 152 pm (electronic ground state properties)

| iron | chromium | oxygen universe abundance | 0.11 mass% | 0.0015 mass% | 1 mass% solar abundance | 0.1 mass% | 0.002 mass% | 0.9 mass% meteorite abundance | 22 mass% | 0.3 mass% | 40 mass% crust abundance | 6.3 mass% | 0.014 mass% | 46 mass% ocean abundance | 3×10^-7 mass% | 6×10^-8 mass% | 86 mass% human abundance | 0.006 mass% | 3×10^-6 mass% | 61 mass% universe molar abundance | 0.002 mol% | 4×10^-5 mol% | 0.08 mol% solar molar abundance | 0.003 mol% | 4×10^-5 mol% | 0.07 mol% meteorite molar abundance | 7.8 mol% | 0.12 mol% | 48 mol% ocean molar abundance | 3.3×10^-8 mol% | 7.1×10^-9 mol% | 33 mol% crust molar abundance | 2.3 mol% | 0.0055 mol% | 60 mol% human molar abundance | 6.7×10^-4 mol% | 4×10^-7 mol% | 24 mol%