Some properties of the carbon group elements

carbon silicon

atomic number 6 14

atomic weight 12.011 28.086

colour of element colourless (diamond 【D】), black (graphite 【G】) gray

melting point (°C) \\>3,500 (D) 1,420

boiling point (°C) 4,827 (D) 2,355

density (grams per cubic centimetre) 3.51 (D), 2.25 (G) 2.33 (25 °C)

oxidation states −4, (+2), +4 −4, (+2), +4

mass number of most common isotopes (terrestrial abundance, percent) 12 (98.89), 13 (1.11) 28 (92.21), 29 (4.70), 30 (3.09)

radioactive isotopes (mass numbers) 10, 11, 14, 15, 16 25–27, 31, 32

heat of fusion (kilocalories per gram atom) 11.1

heat of vaporization (kilocalories per gram atom) 170 (G) 71

heat of sublimation (kilocalories per gram atom) 170 85

heat capacity (calories per mole °C) 1.462 (D), 2.038 (G) 5.086 (0–100 °C)

critical temperature (°C) about 4,920

critical pressure (atmospheres) 1,450

electrical resistivity (microhm-centimetres) 1,375.0 10

hardness (Mohs' scale) 10 (D) 0.5–1.5 (G) 7

crystal structure cubic (D) hexagonal (G) cubic (diamond)

radius

● covalent (angstroms)

0.772 1.17

● ionic (angstroms)

2.60 (−4 ion), 0.16 (+4 ion) 2.71 (−4 ion), 0.42 (+4 ion)

ionization energy (kilocalories per gram atom)

first 261 189

second 564 378

third 1,103 773

fourth 1,486 1,040

electronegativity

(Sanderson) 2.47 1.74

(Pauling) 2.5 1.8

germanium tin lead

atomic number 32 50 82

atomic weight 72.59 118.69 207.19

colour of element white metallic white metallic (beta), gray (alpha) bluish-white metallic

melting point (°C) 937.4 231.9 (alpha) 327.5

boiling point (°C) 2,830 2,270 (alpha) 1,744

density (grams per cubic centimetre)

liquid 6.97 (231.9 °C) 10.51 (400 °C)

solid 5.323 (25 °C) 5.75 (alpha), 7.28 (beta) 11.35 (20 °C)

oxidation states −4, +2, +4 (−4), +2, +4 (−4), +2, +4

mass number of most common isotopes (terrestrial abundance, percent) 70 (20.53), 72 (27.43), 73 (7.76), 74 (36.54), 76 (7.76) 112 (0.96), 114 (0.66), 115 (0.35), 116 (14.3), 117 (7.61), 118 (24.03), 119 (8.58), 120 (32.85), 122 (4.72), 124 (5.94) 204 (1.48), 206 (23.6), 207 (22.6), 208 (52.3)

radioactive isotopes (mass numbers) 65–69, 71, 75, 77, 78 108–111, 113, 121, 123, 125–128 194–203, 205, 209–214

heat of fusion (kilocalories per gram atom) 7.3 1.69 1.21

heat of vaporization (kilocalories per gram atom) 78 61.8 42.3

heat of sublimation (kilocalories per gram atom) 78 47.5

heat capacity (calories per mole °C) 5.372 6.29 (25 °C) 6.53 (15–327.5 °C)

electrical resistivity (microhm-centimetres) 11 20.648

hardness (Mohs' scale) 6 1.5–1.8 1.5

crystal structure cubic (diamond) cubic (diamond, alpha) tetragonal (beta) close-packed, metallic

radius

● covalent (angstroms)

1.22 1.40

● metallic (angstroms)

1.22 1.40 1.54

● ionic (angstroms)

2.72 (−4 ion), 0.73 (+2 ion), 0.53 (+4 ion) 2.94 (−4 ion), 0.93 (+2 ion), 0.71 (+4 ion) 1.20 (+2 ion), 0.84 (+4 ion)

ionization energy (kilocalories per gram atom)

first 184 171 172

second 369 339 348

third 791 705 738

fourth 1,053 941 (977)

electronegativity

(Sanderson) 2.31 2.02 2.01

(Pauling) 1.8 1.8 1.8