zinc cadmium mercury

Atomic number 30 48 80

Atomic weight 65.37 112.41 200.61

Melting point (degrees Celsius) 419.57 321 -38.8

Boiling point (degrees Celsius) 907 767 357

Density, solid (grams per cubic centimetre) 7.14 (20 degrees Celsius) 8.65 (20 degrees Celsius) 14.17 (-38.9 degrees Celsius)

Density, liquid (grams per cubic centimetre) 6.48 (500 degrees Celsius) 7.821 (500 degrees Celsius) 13.546 (20 degrees Celsius)

Valence 2 2 2, 1

Isotopic abundance zinc-64 (50.9), cadmium-106 (1.4), mercury-196 (0.15),

(terrestrial, percent) zinc-66 (27.3), cadmium-108 (1.0), mercury-198 (10.1),

zinc-67 (3.9), cadmium-110 (12.8), mercury-199 (17.0),

zinc-68 (17.4), cadmium-111 (13.0), mercury-200 (23.3),

zinc-70 (0.5) cadmium-112 (24.2), mercury-201 (13.2),

cadmium-113 (12.3), mercury-202 (29.5),

cadmium-114 (28.0), mercury-204 (6.7)

cadmium-116 (7.3)

Radioactive isotopes 60-63, 65, 103-105, 107, 109, 185-195, 197, 203,

(mass numbers) 69, 71, 72 115, 117-119, 121 205, 206

Heat of fusion (calories per gram) 24.1 13.2 2.82

Heat of vaporization (calories per gram) 426 240 70.6

Specific heat 0.092 0.055 0.033

(calories per gram per degree Celsius

at 20 degrees Celsius)

Electrical resistivity 5.75 7.6 95.8

at 20 degrees Celsius (microohm-centimetre)

Hardness (Brinell number) 38.1 29.0 --

Crystal structure hexagonal, hexagonal, rhombohedral

close-packed close-packed

Radius

Metallic (angstroms) 1.332 1.489 1.500

Ionic (+2 ion, angstroms) 0.75 0.99 1.12

Ionization energy

(electron volt)

First 9.36 8.96 10.2

Second 17.89 16.84 18.65

Third 40.0 38.0 --

Electronegativity 1.6 1.7 1.9

(Pauling)