Carbon

Symbol --- C

Abundance --- 0.8% in earth’s crust

Allotropes --- diamond, graphite, fullerenes, graphene, carbon nanotube, carbon nanobud, amorphous carbon, lonsdaleite (hexagonal diamond), diamane, AA’-graphite

Physical state --- solid

Colour --- diamond (transparent), graphite (black),

Discovery --- Egyptians and Sumerians

Atomic no --- 6

Atomic weight --- 12.011

Period --- 2

Group --- 14 or IVA

Block --- p block

Known isotopes --- ₆C¹⁰, ₆C¹¹, ₆C¹², ₆C¹³, ₆C¹⁴, ₆C¹⁵, ₆C¹⁶, ₆C¹⁷, ₆C¹⁸, ₆C¹⁹, ₆C²⁰

Main isotopes --- ₆C¹², ₆C¹³, ₆C¹⁴

Isotopic abundance --- ₆C¹² (98.8%), ₆C¹³ (1.1%), ₆C¹⁴ (trace) (t_1/2 = 5570 years)

Melting Point --- 4000 K (diamond at 125 kbar), 4000 K (graphite at 9 kbar)

Density --- diamond (3.51 g/cm³), graphite (2.26 g/cm³), amorphous carbon (1.9 g/cm³)

Electron configuration --- [He] 2s² 2p²

Electrons per shell --- 2 (1 st shell), 4 (2 nd shell)

Oxidation state --- +4

Valance --- 4

Electronegativity --- 2.5 (Pauling scale)

Electron affinity --- 152.3 KJ/mol

Ionisation energy --- 1086 KJ/mol (1 st), 2352 KJ/mol (2 nd), 4619 KJ/mol (3 rd), 6221 KJ/mol (4 th)

Covalent radius --- 77 pm (sp³), 72.5 pm (sp²), 69 (sp)

Van der Waals radius --- 169.8 pm

Crystal structure --- diamond (transparent) face centered cubic, graphite (black) hexagonal

Molar heat capacity --- diamond [6.15 J/(mol-K)], graphite [8.51 J/(mol-K)]

Specific heat --- graphite 710 J/ (Kg K)

Thermal expansion --- diamond [0.8 μm/ (m K)]

Thermal conductivity --- diamond [900-2300 W/ (m K)]

Speed of sound --- diamond (18345 m/s)

Magnetic type --- diamagnetic

Lattice angles --- π/2, π/2, 2π/3

Lattice constants --- 246.3 pm, 246.3 pm, 670.9 pm

Quantum numbers --- ³P₀

Neutron cross section --- 0.0035

Neutron mass absorption --- 1.5 x 10^-5

Electrical resistivity --- graphite (7.8 μΩ.m)

Mohs hardness --- diamond (10)

graphite (1-2)

Young’s modulus --- diamond (1050 GPa)

Shear modulus --- diamond (475 GPa)

Bulk modulus --- diamond (440 GPa)

Poisson ratio --- diamond (0.1)

Refractive index (546 nm) --- diamond (2.41), graphite (2.15)