89. Actinium
Name: Actinium
Symbol: Ac
Atomic Number: 89
Atomic Mass: (227.0) amu
Melting Point: 1050.0 °C (1323.15 °K, 1922.0 °F)
Boiling Point: 3200.0 °C (3473.15 °K, 5792.0 °F)
Number of Protons/Electrons: 89
Number of Neutrons: 138
Classification: Rare Earth
Crystal Structure: Cubic
Density(293 K): 10.07 g/cm3
Color: Silvery
Actinium is dangerously radioactive. The chemical behaviour of actinium is similar to that of the rare earths, particularly lanthanum. It is found naturally in uranium ores and actinium is 150 times more radioactive than radium.
Actinium was discovered in 1899 by Andre-Louis Debierne, a French chemist, who separated it from pitchblende. Friedrich Otto Giesel independently discovered actinium in 1902. The chemical behavior of actinium is similar to that of the rare earth lanthanum.
The word actinium comes from the Greek aktis, aktinos, meaning beam or ray.
Actinium-227 is extremely radioactive, and in terms of its potential for radiation induced health effects, actinium-227 is about as dangerous as plutonium. Ingesting even small amounts of actinium-227 would represent a serious health hazard.
Quick links
| Non-metals |
H, C, N,
O, P, S,
Se |
| Halogens |
F, Cl, Br,
I, At |
| Alkali metals |
Li, Na, K,
Rb, Cs, Fr |
| Alkaline Earth |
Be, Mg, Ca,
Sr, Ba, Ra |
| Transition metals |
Sc, Ti, V,
Cr, Mn, Fe,
Co, Ni, Cu,
Zn, Y, Zr,
Nb, Mo, Tc,
Ru, Rh, Pd,
Ag, Cd, Hf,
Ta, W, Re,
Os, Ir, Pt,
Au, Hg, Rf,
Db, Sg, Bh,
Hs, Mt, Ds,
Rg, Uub |
| Metalloids |
B, Si, Ge,
As, Sb, Te,
Po |
| Other metals |
Al, Ga, In,
Sn, Tl, Pb,
Bi |
| Rare Earth |
Lu, Lr, La,
Ce, Pr, Nd,
Pm, Sm, Eu,
Gd, Tb, Dy,
Ho, Er, Tm,
Yb, Ac, Th,
Pa, U, Np,
Pu, Am, Cm,
Bk, Cf, Es,
Fm, Md, No |
| Noble gases |
He, Ne, Ar,
Kr, Xe, Rn |
Back to table
Another interactive
table of elements Quantum physics Quantum fields
|
