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At Astatine
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

85
At
Astatine
Element 85 of Periodic table is Astatine with atomic number 85, atomic weight 210. Astatine, symbol At, has a Face Centered Cubic structure and Silver color. Astatine is a Halogens element. It is part of group 17 (fluorine family). Know everything about Astatine Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
85 At - Astatine | SchoolMyKids

Astatine is a very rare radioactive chemical element with the chemical symbol At and atomic number 85. It occurs on Earth as the decay product of various heavier elements. All its isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.

It belongs to group 17 of the periodic table having trivial name halogens.

Astatine Facts

Read key information and facts about element Astatine

NameAstatine
Atomic Number85
Atomic SymbolAt
Atomic Weight210
PhaseSolid
ColorSilver
Appearanceunknown, probably metallic
ClassificationHalogens
Group in Periodic Table17
Group Namefluorine family
Period in Periodic Tableperiod 6
Block in Periodic Tablep -block
Electronic Configuration[Xe] 4f14 5d10 6s2 6p5
Electronic Shell Structure (Electrons per shell)2, 8, 18, 32, 18, 7
Melting Point575 K
Boiling Point-
CAS NumberCAS7440-68-8
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Astatine on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 85 to find Astatine on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Astatine on periodic table look for cross section of group 17 and period 6 in the modern periodic table.

Astatine History

The element Astatine was discovered by R. Corson,R. MacKenzie and E. Segrè in year 1940 in United States. Astatine was first isolated by in . Astatine derived its name from the Greek astatos, 'unstable'.

Obtained by bombarding bismuth with alpha particles. Later determined to occur naturally in minuscule quantities (<25 grams in earth's crust).

Astatine Presence: Abundance in Nature and Around Us

The table below shows the abundance of Astatine in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe--
Abundance in Sun--
Abundance in Meteorites--
Abundance in Earth's Crust--
Abundance in Oceans--
Abundance in Humans--

Crystal Structure of Astatine

The solid state structure of Astatine is Face Centered Cubic.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group Name- 85 At Astatine - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number-
Crystal StructureFace Centered Cubic

Astatine Atomic and Orbital Properties

Astatine atoms have 85 electrons and the electronic shell structure is [2, 8, 18, 32, 18, 7] with Atomic Term Symbol (Quantum Numbers) 2P3/2.

Atomic Number85
Number of Electrons (with no charge)85
Number of Protons85
Mass Number210
Number of Neutrons125
Shell structure (Electrons per energy level)2, 8, 18, 32, 18, 7
Electron Configuration[Xe] 4f14 5d10 6s2 6p5
Valence Electrons6s2 6p5
Valence (Valency)7
Main Oxidation States-1, 1
Oxidation States-1, 1, 3, 5, 7
Atomic Term Symbol (Quantum Numbers)2P3/2

Bohr Atomic Model of Astatine - Electrons per energy level

85 At Astatine - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Astatine - neutral Astatine atom

Abbreviated electronic configuration of Astatine

The ground state abbreviated electronic configuration of Neutral Astatine atom is [Xe] 4f14 5d10 6s2 6p5. The portion of Astatine configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 6s2 6p5, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Astatine

Complete ground state electronic configuration for the Astatine atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p5

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Astatine
    Atomic Structure of Astatine

    Astatine atomic radius is 127 pm, while it's covalent radius is - .

    Atomic Radius Calculated

    127 pm (1.27 Å)

    Atomic Radius Empirical

    - (0 Å)

    Atomic Volume-
    Covalent Radius-
    Van der Waals Radius202 pm
    Neutron Cross Section-
    Neutron Mass Absorption -

    Atomic Spectrum of Astatine

    Atomic Spectrum of Astatine | SchoolMyKids

    Astatine Chemical Properties: Astatine Ionization Energies and electron affinity

    The electron affinity of Astatine is 270.1 kJ/mol.

    Valence7
    Electronegativity2.2
    ElectronAffinity270.1 kJ/mol

    Ionization Energy of Astatine

    Refer to table below for Ionization energies of Astatine

    Ionization energy numberEnthalpy - kJ/mol
    1st899.003

    Astatine Physical Properties

    Refer to below table for Astatine Physical Properties

    Density-
    Molar Volume-

    Elastic Properties

    Young Modulus-
    Shear Modulus-
    Bulk Modulus -
    Poisson Ratio-

    Hardness of Astatine - Tests to Measure of Hardness of Element

    Mohs Hardness-
    Vickers Hardness-
    Brinell Hardness-

    Astatine Electrical Properties

    Astatine is Conductor of electricity. Refer to table below for the Electrical properties ofAstatine

    Electrical Conductivity-
    Resistivity-
    Superconducting Point-

    Astatine Heat and Conduction Properties

    Thermal Conductivity2 W/(m K)
    Thermal Expansion-

    Astatine Magnetic Properties

    Magnetic Type-
    Curie Point-
    Mass Magnetic Susceptibility-
    Molar Magnetic Susceptibility-
    Volume Magnetic Susceptibility-

    Optical Properties of Astatine

    Refractive Index-

    Acoustic Properties of Astatine

    Speed of Sound-

    Astatine Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Astatine

    Melting Point575 K (301.85°C, 575.33 °F)
    Boiling Point- (-273.15°C, -459.66999999999996 °F)
    Critical Temperature-
    Superconducting Point-

    Enthalpies of Astatine

    Heat of Fusion6 kJ/mol
    Heat of Vaporization40 kJ/mol
    Heat of Combustion-

    Astatine Isotopes - Nuclear Properties of Astatine

    Astatine has 31 isotopes, with between 193 and 223 nucleons. Astatine has 0 stable naturally occuring isotopes.

    Isotopes of Astatine - Naturally occurring stable Isotopes: -.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    193At85108193Synthetic
    194At85109194Synthetic
    195At85110195Synthetic
    196At85111196Synthetic
    197At85112197Synthetic
    198At85113198Synthetic
    199At85114199Synthetic
    200At85115200Synthetic
    201At85116201Synthetic
    202At85117202Synthetic
    203At85118203Synthetic
    204At85119204Synthetic
    205At85120205Synthetic
    206At85121206Synthetic
    207At85122207Synthetic
    208At85123208Synthetic
    209At85124209Synthetic
    210At85125210Synthetic8.06 hBetaPlusDecay
    211At85126211Synthetic
    212At85127212Synthetic
    213At85128213Synthetic
    214At85129214Synthetic
    215At85130215Synthetic
    216At85131216Synthetic
    217At85132217Synthetic
    218At85133218Synthetic
    219At85134219Synthetic
    220At85135220Synthetic
    221At85136221Synthetic
    222At85137222Synthetic
    223At85138223Synthetic

    Database Search

    List of unique identifiers to search the element in various chemical registry databases

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7440-68-8
    RTECS Number-
    CID Number -
    Gmelin Number-
    NSC Number-