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Am Americium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

95
Am
Americium
Element 95 of Periodic table is Americium with atomic number 95, atomic weight 243. Americium, symbol Am, has a Simple Hexagonal structure and Silver color. Americium is a Actinide element. It is part of group null (). Know everything about Americium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
95 Am - Americium | SchoolMyKids

Americium is a radioactive transuranic chemical element with symbol Am and atomic number 95. This member of the Actinide series is located in the periodic table under the Lanthanide element europium, and thus by analogy was named after the Americas. Americium was first produced in 1944 by the group of Glenn T.Seaborg from Berkeley, California, at the metallurgical laboratory of University of Chicago.

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

Americium Facts

Read key information and facts about element Americium

NameAmericium
Atomic Number95
Atomic SymbolAm
Atomic Weight243
PhaseSolid
ColorSilver
Appearancesilvery white
ClassificationActinide
Group in Periodic Table-
Group Name
Period in Periodic Tableperiod 7
Block in Periodic Tablef -block
Electronic Configuration[Rn] 5f7 7s2
Electronic Shell Structure (Electrons per shell)2, 8, 18, 32, 25, 8, 2
Melting Point1449 K
Boiling Point2284 K
CAS NumberCAS7440-35-9
Neighborhood Elements
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 Americium 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 95 to find Americium 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 Americium on periodic table look for cross section of group - and period 7 in the modern periodic table.

Americium History

The element Americium was discovered by G. T. Seaborg,R. A. James,O. Morgan and A. Ghiorso in year 1944 in United States. Americium was first isolated by in . Americium derived its name from The Americas, as the element was first synthesized on the continent, by analogy with europium.

Prepared by irradiating plutonium with neutrons during theManhattan Project.

Americium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Americium 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 Americium

The solid state structure of Americium is Simple Hexagonal.

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
346.81 pm346.81 pm1124.1 pm

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

alphabetagamma
π/2 π/2 2 π/3

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 NameP63/mmc 95 Am Americium - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number194
Crystal StructureSimple Hexagonal

Americium Atomic and Orbital Properties

Americium atoms have 95 electrons and the electronic shell structure is [2, 8, 18, 32, 25, 8, 2] with Atomic Term Symbol (Quantum Numbers) 8S7/2.

Atomic Number95
Number of Electrons (with no charge)95
Number of Protons95
Mass Number243
Number of Neutrons148
Shell structure (Electrons per energy level)2, 8, 18, 32, 25, 8, 2
Electron Configuration[Rn] 5f7 7s2
Valence Electrons5f7 7s2
Valence (Valency)4
Main Oxidation States3
Oxidation States2, 3, 4, 5, 6, 7
Atomic Term Symbol (Quantum Numbers)8S7/2

Bohr Atomic Model of Americium - Electrons per energy level

95 Am Americium - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Americium - neutral Americium atom

Abbreviated electronic configuration of Americium

The ground state abbreviated electronic configuration of Neutral Americium atom is [Rn] 5f7 7s2. The portion of Americium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Rn]. 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 5f7 7s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Americium

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

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p6 5f7 7s2

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 Americium
    Atomic Structure of Americium

    Americium atomic radius is 175 pm, while it's covalent radius is - .

    Atomic Radius Calculated

    175 pm (1.75 Å)

    Atomic Radius Empirical

    175 pm (1.75 Å)

    Atomic Volume17.63 cm3/mol
    Covalent Radius-
    Van der Waals Radius-
    Neutron Cross Section74
    Neutron Mass Absorption -

    Atomic Spectrum of Americium

    Atomic Spectrum of Americium | SchoolMyKids

    Americium Chemical Properties: Americium Ionization Energies and electron affinity

    The electron affinity of Americium is - .

    Valence4
    Electronegativity1.13
    ElectronAffinity-

    Ionization Energy of Americium

    Refer to table below for Ionization energies of Americium

    Ionization energy numberEnthalpy - kJ/mol
    1st578

    Americium Physical Properties

    Refer to below table for Americium Physical Properties

    Density13.67 g/cm3
    Molar Volume17.63 cm3/mol

    Elastic Properties

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

    Hardness of Americium - Tests to Measure of Hardness of Element

    Mohs Hardness-
    Vickers Hardness-
    Brinell Hardness-

    Americium Electrical Properties

    Americium is Conductor of electricity. Refer to table below for the Electrical properties ofAmericium

    Electrical Conductivity-
    Resistivity-
    Superconducting Point0.6

    Americium Heat and Conduction Properties

    Thermal Conductivity10 W/(m K)
    Thermal Expansion-

    Americium Magnetic Properties

    Magnetic TypeParamagnetic
    Curie Point-
    Mass Magnetic Susceptibility5.15e-8 m3/kg
    Molar Magnetic Susceptibility1.251e-8 m3/mol
    Volume Magnetic Susceptibility0.000704

    Optical Properties of Americium

    Refractive Index-

    Acoustic Properties of Americium

    Speed of Sound-

    Americium Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Americium

    Melting Point1449 K (1175.85°C, 2148.5299999999997 °F)
    Boiling Point2284 K (2010.85°C, 3651.5299999999997 °F)
    Critical Temperature-
    Superconducting Point0.6

    Enthalpies of Americium

    Heat of Fusion-
    Heat of Vaporization-
    Heat of Combustion-

    Americium Isotopes - Nuclear Properties of Americium

    Americium has 19 isotopes, with between 231 and 249 nucleons. Americium has 0 stable naturally occuring isotopes.

    Isotopes of Americium - Naturally occurring stable Isotopes: -.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    231Am95136231Synthetic
    232Am95137232Synthetic
    233Am95138233Synthetic
    234Am95139234Synthetic
    235Am95140235Synthetic
    236Am95141236Synthetic
    237Am95142237Synthetic
    238Am95143238Synthetic
    239Am95144239Synthetic
    240Am95145240Synthetic
    241Am95146241Synthetic
    242Am95147242Synthetic
    243Am95148243Synthetic7388 yearsAlphaEmission
    244Am95149244Synthetic
    245Am95150245Synthetic
    246Am95151246Synthetic
    247Am95152247Synthetic
    248Am95153248Synthetic
    249Am95154249Synthetic

    Database Search

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

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7440-35-9
    RTECS Number-
    CID Number -
    Gmelin Number-
    NSC Number-

    Compare Americium with other elements

    Compare Americium with all Group elements

    Compare Americium with all Period 7 elements

    Compare Americium with all Actinide elements