radium

Radium

Name:Radium

Symbol:Ra

Atomic Number:88

Atomic Mass:226

Density: 41.09 g/cm^3

Melting Point:700 �C

Boiling Point:1737 �C

Group Number:2

Group Name:Alkaline Earth Metals

Standard State:solid at room temperature

Color:metallic

Classification:Metallic

Radium paint was used in the mid 1900s to paint the hands and numbers

of some clocks and watches. The paint was composed of radium salts and

a phosphor and glowed in the dark.

Pure metallic radium is brilliant white when freshly prepared, but

blackens on exposure to air, probably due to formation of the nitride.

It exhibits luminescence, as do its salts; it decomposes in water and

is somewhat more volatile than barium. Radium imparts a carmine red

colour to a flame.

Radium emits a, b, and g rays and when mixed with beryllium produces

neutrons. Inhalation, injection, or body exposure to radium can cause

cancer and other body disorders. alkaline earth metal, white but

tarnishes black upon exposure to air, luminesces, decomposes in water,

emits radioactive radon gas, disintegrated radioactively until it

reaches stable lead, radiological hazard, a, b, and g emitter,

exposure to radium can cause cancer and other body disorders. Radium

is over a million times more radioactive than the same mass of

uranium.

Isolation

All isotopes of radium are radioactive and there is only ever any need

to make radium metal on very small scales for research purposes.

Radium is extremely scarce but found in uranium ores such as

pitchblende at slightly more than 1g in 10 tonnes of ore. It may be

made on very small scale by the electrolysis of molten radium

chloride, RaCl[2]. This was first done using a mercury cathode, which

gave radium amalgam. The metal was obtained by distillation away from

the amalgam.