carbon, hydrogen, helium

carbon (chemical element) | hydrogen (chemical element) | helium (chemical element)

Periodic table location

Images

| carbon | hydrogen | helium atomic symbol | C | H | He atomic number | 6 | 1 | 2 short electronic configuration | [He]2s^22p^2 | 1s^1 | 1s^2 Aufbau diagram | 2p 2s | 1s | 1s block | p | s | s group | 14 | 1 | 18 period | 2 | 1 | 1 atomic mass | 12.011 u | 1.008 u | 4.002602 u half-life | (stable) | (stable) | (stable)

| carbon | hydrogen | helium phase at STP | solid | gas | gas melting point | 3550 °C | -259.14 °C | boiling point | 4027 °C | -252.87 °C | -268.93 °C critical temperature | | 32.97 K | 5.19 K critical pressure | | 1.293 MPa | 0.227 MPa molar heat of fusion | 105 kJ/mol | 0.558 kJ/mol | 0.02 kJ/mol molar heat of vaporization | 715 kJ/mol | 0.452 kJ/mol | 0.083 kJ/mol specific heat at STP | 710 J/(kg K) | 14300 J/(kg K) | 5193.1 J/(kg K) adiabatic index | | 7/5 | 5/3 (properties at standard conditions)

| carbon | hydrogen | helium density | 2.26 g/cm^3 | 8.99×10^-5 g/cm^3 | 1.785×10^-4 g/cm^3 molar volume | 5.315 cm^3/mol | 11200 cm^3/mol | 22420 cm^3/mol Mohs hardness | 0.5 (between talc and gypsum) | | bulk modulus | 33 GPa | | refractive index | 2.417 | 1.000132 | 1.000035 sound speed | 18350 m/s | 1270 m/s | 970 m/s thermal expansion | 7.1×10^-6 K^(-1) | | thermal conductivity | 140 W/(m K) | 0.1805 W/(m K) | 0.1513 W/(m K) (properties at standard conditions)

| carbon | hydrogen | helium electrical type | conductor | | resistivity | 1×10^-5 Ω m (ohm meters) | | electrical conductivity | 100000 S/m (siemens per meter) | | magnetic type | diamagnetic | diamagnetic | diamagnetic volume magnetic susceptibility | -1.4×10^-5 | -2.23×10^-9 | -1.05×10^-9 mass magnetic susceptibility | -6.2×10^-9 m^3/kg (cubic meters per kilogram) | -2.48×10^-8 m^3/kg (cubic meters per kilogram) | -5.9×10^-9 m^3/kg (cubic meters per kilogram) molar magnetic susceptibility | -7.45×10^-11 m^3/mol (cubic meters per mole) | -4.999×10^-11 m^3/mol (cubic meters per mole) | -2.36×10^-11 m^3/mol (cubic meters per mole) work function | 5 eV (Polycrystalline) | | threshold frequency | 1.209×10^15 Hz (hertz) | | color | (black) | (colorless) | (colorless) refractive index | 2.417 | 1.000132 | 1.000035

| carbon | hydrogen | helium valence | 4 | 1 | 0 electronegativity | 2.55 | 2.2 | electron affinity | 153.9 kJ/mol (kilojoules per mole) | 72.8 kJ/mol (kilojoules per mole) | 0 kJ/mol (kilojoules per mole) first ionization energy | 1086.5 kJ/mol (kilojoules per mole) | 1312 kJ/mol (kilojoules per mole) | 2372.3 kJ/mol (kilojoules per mole) ionization energies | 1086.5 kJ/mol | 2352.6 kJ/mol | 4620.5 kJ/mol | 6222.7 kJ/mol | 37831 kJ/mol | 47277 kJ/mol | 1312 kJ/mol | 2372.3 kJ/mol | 5250.5 kJ/mol

Reactivity

| carbon | hydrogen | helium term symbol | ^3P_0 | ^2S_(1/2) | ^1S_0 atomic radius | 70 pm | 25 pm | 31 pm covalent radius | 76 pm | 31 pm | 28 pm van der Waals radius | 170 pm | 120 pm | 140 pm (electronic ground state properties)

| carbon | hydrogen | helium universe abundance | 0.5 mass% | 75 mass% | 23 mass% solar abundance | 0.3 mass% | 75 mass% | 23 mass% meteorite abundance | 1.5 mass% | 2.4 mass% | crust abundance | 0.18 mass% | 0.15 mass% | 5.5×10^-7 mass% ocean abundance | 0.0028 mass% | 11 mass% | 7.2×10^-10 mass% human abundance | 23 mass% | 10 mass% | universe molar abundance | 0.05 mol% | 93 mol% | 7.2 mol% solar molar abundance | 0.03 mol% | 93 mol% | 7.4 mol% meteorite molar abundance | 1.8 mol% | 17 mol% | ocean molar abundance | 0.0014 mol% | 66 mol% | 1.1×10^-9 mol% crust molar abundance | 0.31 mol% | 3.1 mol% | 3×10^-6 mol% human molar abundance | 12 mol% | 62 mol% |

| carbon | hydrogen | helium half-life | (stable) | (stable) | (stable) stable isotopes | C-12 (98.89%) | C-13 (1.11%) | H-1 (99.985%) | H-2 (1.5×10^-4) | He-4 (99.999863%) | He-3 (1.37×10^-6) nuclear spin | C-8: 0^+ | C-9: 3/2^- | C-10: 0^+ | C-11: 3/2^- | C-12: 0^+ | C-13: 1/2^- | C-14: 0^+ | C-15: 1/2^+ | C-16: 0^+ | C-17: 3/2^+ | C-18: 0^+ | C-19: 1/2^+ | C-20: 0^+ | C-21: 1/2^+ | C-22: 0^+ | H-1: 1/2^+ | H-2: 1^+ | H-3: 1/2^+ | H-4: 2^- | H-5: 1/2^+ | H-6: 2^- | H-7: 1/2^+ | He-3: 1/2^+ | He-4: 0^+ | He-5: 3/2^- | He-6: 0^+ | He-7: 3/2^- | He-8: 0^+ | He-9: 1/2^+ | He-10: 0^+ unstable isotopes | C-14 (5700 yr) | C-11 (20.334 min) | C-10 (19.29 s) | C-15 (2.449 s) | C-16 (747 ms) | C-17 (193 ms) | C-9 (126.5 ms) | C-18 (92 ms) | C-19 (49 ms) | C-20 (14 ms) | C-22 (6.2 ms) | C-21 (30 ns) | C-8 (2 zs) | H-3 (12.32 yr) | H-6 (0.29 zs) | H-4 (0.139 zs) | H-5 (0.08 zs) | H-7 (0.023 zs) | He-6 (806.7 ms) | He-8 (119 ms) | He-9 (7 zs) | He-7 (3.04 zs) | He-10 (1.52 zs) | He-5 (0.76 zs) neutron cross-section | 0.0035 b | 0.332 b | 0.007 b neutron mass absorption | 1.5×10^-5 m^2/kg | 0.011 m^2/kg | 1×10^-5 m^2/kg

| carbon | hydrogen | helium CAS number | 7440-44-0 | 1333-74-0 | 7440-59-7 PubChem CID number | | 783 | 23987