Americium - Am

Atomic number

95

Atomic mass

(243) g.mol ^-1

Electronegativity according to Pauling

unknown

Density

13.67 g.cm^-3 at 20°C

Melting point

994 °C

Boiling point

2607 °C

Vanderwaals radius

unknown

Ionic radius

unknown

Isotopes

8

Electronic shell

[ Rn ] 5f⁷ 7s²

Energy of first ionisation

578 kJ.mol ^-1

Discovered by

G.T. Seaborg in 1945

Humans may be exposed to higher concentrations of americium through food, breathing or skin contact, because of the release of americium during nuclear production and nuclear accidents. People that work in nuclear power plants and people that live near nuclear power plants may be exposed to higher levels of americium.

The radiation from exposure to americium is the primary cause of health effects from absorbed americium. Americium moves rapidly through the body after uptake and is concentrated within the bones for a long period of time. During this storage americium will slowly decay and release radioactive particles and rays. These rays can cause alteration of genetic materials and bone cancers.

Damage to organs due to americium exposure is highly unlikely for humans, because americium is accumulated in organs only a short period of time.

Americium consists mainly of manmade radioactive isotopes. These may be present in soils and waters in very small amounts as a result of atmospheric nuclear weapons testing prior to the nuclear test ban of 1963. Americium from atmospheric nuclear weapons tests may remain in the atmosphere for decades travelling all around the world and settling slowly to earth. Its isotopes decay very slowly in the environment and as a result they can do harm to plants and animals. When animals are exposed to extreme levels of americium, results may be damage to organs such as the lungs, liver and thyroid.

Americium that is present in soils may end up in plants, but only in small amounts. Usually americium particles are stored in parts of the plant that animals will not eat. Within fish very little americium builds up in the flesh or other edible parts and as a result it will not accumulate within food chains.