Astatine

Images

Image

Attribution: None

Animated Astatine

History

From the Greek astatos meaning unstable. Synthesized in 1940 by D.R. Corson, K.R. MacKenzie, and E. Segre at the University of California by bombarding bismuth with alpha particles. The longest-lived isotopes, with naturally occurring uranium and thorium isotopes, and traces of 217At are equilibrium with 233U and 239Np resulting from integration of thorium and uranium with naturally produced neutrons. The total amount of astatine present in the earth's crust, however, is less than 1 oz.

General Info

AtomicNumber
85
Symbol
At
Name
Astatine

Atomic Info

Appearance
AtomicWeight
[210]
Color
754F45
ElectronicConfiguration
[Xe] 4f14 5d10 6s2 6p5
ElectronegativityInPauling
2.2
AtomicRadiusInPM
IonRadiusInPM
62 (+7)
VanDerWaalsRadiusInPM
IEinKJmol
920
EAinKJmol
-270
OxidationStates
-1, 1, 3, 5
StandardState
solid
BondingType
covalent network
MeltingPoint
575
BoilingPoint
610
Density
0
State
Metalloid
DiscoveredYear
1940