Periodic
Table
|
Astatine
|
Symbol
|
At
|
|
Atomic
Number
|
85
|
|
Group
|
halogens
|
Relative
Atomic
Mass
12C
=
12.0000
|
[
210
]
209.9871
8.1(4)
hour
|
|
Significant
Atomic
Mass
|
217
Neutrons
132
|
|
Isotop
|
211
210.9875
7.21(1)
hour
|
|
Atomic
Radius
pm
|
140
|
First
Ionisation
Energy
kJ
mol
-1
|
930
|
|
Ionization energy (eV)
|
|
|
Electronegativity
|
2.2
|
|
Density kg
m
-3
|
-
|
|
Molar
Volume
cm
3
|
-
|
Thermal
Conductivity
W
m
-1
K
-1
|
1.7
[300
K]
|
|
Melting
Point
K
|
575
(est.)
|
|
Boiling
Point
K
|
610
(est.)
|
|
Number
of
Isotopes
|
29
|
|
Inner
+
outer
Shells
|
|
|
Inner
+
outer
Orbitals
|
|
|
Filling
Orbital
|
|
Ground
State
Electron
Configuration
|
|
|
|
Ground
State
Electron
Configuration
with
free
Orbitals (n=1)
|
|
|
|
|
Ground
State
Electron
Configuration
with
compressed
Orbitals (n=96)
0,0,0,0,32,64
|
|
|
|
|
Singularity
|
|
|
|
|
|
s
|
p
|
d
|
f
|
g
|
h
|
i
|
j
|
|
1
|
2
|
|
|
|
|
|
|
|
|
2
|
2
|
6
|
|
|
|
|
|
|
|
3
|
2
|
6
|
10
|
|
|
|
|
|
|
4
|
2
|
6
|
10
|
14
|
|
|
|
|
|
5
|
2
|
6
|
10
|
14
|
18
|
|
|
|
|
6
|
2
|
5
|
1
|
10
|
14
|
18
|
22
|
|
|
|
7
|
|
|
|
|
|
|
|
|
|
8
|
|
|
|
|
|
|
|
|
|
|
|
|
Term
Symbol
|
2Pº3/2
|
|
Discovery
|
Discovered
by
D.R.
Corson,
K.R.
Mackenzie
and
E.
Segré
(Berkeley,
USA)
in
1940
|
|
Name
Derived
From
|
Greek
astatos
meaning
'unstable'
|
|
