Atomic number:48

Group numbers:12

Period:5

Electronic configuration:[Kr] 4d¹⁰ 5s²

Formal oxidation number:+2

Electronegativities:1.69

Atomic radius / pm:148.9

Relative atomic mass:112.411 ± 0.008

 

Cadmium was discovered by Friedrich Strohmeyer (DE) in 1817. The origin of the name comes from the Latin word cadmia meaning calamine (zinc carbonate, ZnCO3), or from the Greek word kadmeia with the same meaning. It is a soft, malleable, blue-white metal that tarnishes in air, soluble in acids, insoluble in alkalis. Boiling cadmium gives off a weird, yellow-coloured vapour that is poisonous. Cadmium can cause a variety of health problems, including kidney failure and high blood pressure. Cadmium is obtained as a by product of zinc refining. The mayor use of cadmium is in electroplating of steel to protect it from corrosion. It is also used to make nickel-cadmium batteries. The ability of cadmium to adsorb neutrons has made it of great importance in the design of nuclear reactors. Its compounds are found in paint pigments and a wide variety of intense colours.

Density / g dm^-3:8650 (293 K)

 7996 (m.p.)

Molar volume / cm³mol^-1:13.00 (293 K)

 14.06 (m.p.)

Electrical resistivity / μΩcm:6.83 (20 °C)

Thermal conductivity / W m^-1K^-1:96.8

Melting point / °C:312.07

Boiling point / °C:767

Heat of fusion / kJ mol^-1:6.11

Heat of vaporization / kJ mol^-1:100

Heat of atomization / kJ mol^-1:112.05

1st ionization energy / kJ mol^-1:867.78

2nd ionization energy / kJ mol^-1:1631.42

3rd ionization energy / kJ mol^-1:3616.30

in the atmosphere / ppm:-

in the Earth's crust / ppm:0.098

in the oceans / ppm:0.0001