• Explore SchoolMyKids in English

Pm Promethium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

61
Pm
Promethium
Element 61 of Periodic table is Promethium with atomic number 61, atomic weight 145. Promethium, symbol Pm, has a Simple Hexagonal structure and Silver color. Promethium is a Lanthanide element. It is part of group null (). Know everything about Promethium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
61 Pm - Promethium | SchoolMyKids

Promethium, originally prometheum, is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a Lanthanide, which forms salts when combined with other elements.

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

Promethium Facts

Read key information and facts about element Promethium

NamePromethium
Atomic Number61
Atomic SymbolPm
Atomic Weight145
PhaseSolid
ColorSilver
Appearancemetallic
ClassificationLanthanide
Group in Periodic Table-
Group Name
Period in Periodic Tableperiod 6
Block in Periodic Tablef -block
Electronic Configuration[Xe] 4f5 6s2
Electronic Shell Structure (Electrons per shell)2, 8, 18, 23, 8, 2
Melting Point1373 K
Boiling Point3273 K
CAS NumberCAS7440-12-2
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 Promethium 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 61 to find Promethium 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 Promethium on periodic table look for cross section of group - and period 6 in the modern periodic table.

Promethium History

The element Promethium was discovered by S. Wu,E.G. Segrè and H. Bethe in year 1942 in United States. Promethium was first isolated by Charles D. Coryell,Jacob A. Marinsky,Lawrence E. Glendenin, and Harold G. Richter in 1945. Promethium derived its name from Prometheus of Greek mythology who stole fire from the Gods and gave it to humans.

It was probably first prepared in 1942 by bombarding neodymium and praseodymium with neutrons, but separation of the element could not be carried out. Isolation was performed under the Manhattan Project in 1945.

Promethium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Promethium 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-0.005
Abundance in Meteorites--
Abundance in Earth's Crust--
Abundance in Oceans--
Abundance in Humans--

Crystal Structure of Promethium

The solid state structure of Promethium 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

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- 61 Pm Promethium - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number-
Crystal StructureSimple Hexagonal

Promethium Atomic and Orbital Properties

Promethium atoms have 61 electrons and the electronic shell structure is [2, 8, 18, 23, 8, 2] with Atomic Term Symbol (Quantum Numbers) 6H5/2.

Atomic Number61
Number of Electrons (with no charge)61
Number of Protons61
Mass Number145
Number of Neutrons84
Shell structure (Electrons per energy level)2, 8, 18, 23, 8, 2
Electron Configuration[Xe] 4f5 6s2
Valence Electrons4f5 6s2
Valence (Valency)3
Main Oxidation States3
Oxidation States2, 3
Atomic Term Symbol (Quantum Numbers)6H5/2

Bohr Atomic Model of Promethium - Electrons per energy level

61 Pm Promethium - Electron Shell Structure | SchoolMyKids
nspdf

Ground State Electronic Configuration of Promethium - neutral Promethium atom

Abbreviated electronic configuration of Promethium

The ground state abbreviated electronic configuration of Neutral Promethium atom is [Xe] 4f5 6s2. The portion of Promethium 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 4f5 6s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Promethium

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

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f5 6s2

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 Promethium
    Atomic Structure of Promethium

    Promethium atomic radius is 205 pm, while it's covalent radius is - .

    Atomic Radius Calculated

    205 pm (2.05 Å)

    Atomic Radius Empirical

    185 pm (1.85 Å)

    Atomic Volume20.23 cm3/mol
    Covalent Radius-
    Van der Waals Radius-
    Neutron Cross Section8000
    Neutron Mass Absorption -

    Atomic Spectrum of Promethium

    Atomic Spectrum of Promethium | SchoolMyKids

    Promethium Chemical Properties: Promethium Ionization Energies and electron affinity

    The electron affinity of Promethium is 50 kJ/mol.

    Valence3
    Electronegativity1.13
    ElectronAffinity50 kJ/mol

    Ionization Energy of Promethium

    Refer to table below for Ionization energies of Promethium

    Ionization energy numberEnthalpy - kJ/mol
    1st540
    2nd1050
    3rd2150
    4th3970

    Promethium Physical Properties

    Refer to below table for Promethium Physical Properties

    Density7.264 g/cm3
    Molar Volume20.23 cm3/mol

    Elastic Properties

    Young Modulus46
    Shear Modulus18 GPa
    Bulk Modulus 33 GPa
    Poisson Ratio0.28

    Hardness of Promethium - Tests to Measure of Hardness of Element

    Mohs Hardness-
    Vickers Hardness-
    Brinell Hardness-

    Promethium Electrical Properties

    Promethium is Conductor of electricity. Refer to table below for the Electrical properties ofPromethium

    Electrical Conductivity1300000 S/m
    Resistivity7.5e-7 m Ω
    Superconducting Point-

    Promethium Heat and Conduction Properties

    Thermal Conductivity15 W/(m K)
    Thermal Expansion0.000011 /K

    Promethium Magnetic Properties

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

    Optical Properties of Promethium

    Refractive Index-

    Acoustic Properties of Promethium

    Speed of Sound-

    Promethium Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Promethium

    Melting Point1373 K (1099.85°C, 2011.73 °F)
    Boiling Point3273 K (2999.85°C, 5431.73 °F)
    Critical Temperature-
    Superconducting Point-

    Enthalpies of Promethium

    Heat of Fusion7.7 kJ/mol
    Heat of Vaporization290 kJ/mol
    Heat of Combustion-

    Promethium Isotopes - Nuclear Properties of Promethium

    Promethium has 38 isotopes, with between 126 and 163 nucleons. Promethium has 1 stable naturally occuring isotopes.

    Isotopes of Promethium - Naturally occurring stable Isotopes: None.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    126Pm6165126Synthetic
    127Pm6166127Synthetic
    128Pm6167128Synthetic
    129Pm6168129Synthetic
    130Pm6169130Synthetic
    131Pm6170131Synthetic
    132Pm6171132Synthetic
    133Pm6172133Synthetic
    134Pm6173134Synthetic
    135Pm6174135Synthetic
    136Pm6175136Synthetic
    137Pm6176137Synthetic
    138Pm6177138Synthetic
    139Pm6178139Synthetic
    140Pm6179140Synthetic
    141Pm6180141Synthetic
    142Pm6181142Synthetic
    143Pm6182143Synthetic
    144Pm6183144Synthetic
    145Pm6184145Synthetic17.73 yearsElectronCapture
    146Pm6185146Synthetic
    147Pm6186147Synthetic
    148Pm6187148Synthetic
    149Pm6188149Synthetic
    150Pm6189150Synthetic
    151Pm6190151Synthetic
    152Pm6191152Synthetic
    153Pm6192153Synthetic
    154Pm6193154Synthetic
    155Pm6194155Synthetic
    156Pm6195156Synthetic
    157Pm6196157Synthetic
    158Pm6197158Synthetic
    159Pm6198159Synthetic
    160Pm6199160Synthetic
    161Pm61100161Synthetic
    162Pm61101162Synthetic
    163Pm61102163Synthetic

    Database Search

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

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7440-12-2
    RTECS Number-
    CID Number -
    Gmelin Number-
    NSC Number-

    Compare Promethium with other elements

    Compare Promethium with all Group elements

    Compare Promethium with all Period 6 elements

    Compare Promethium with all Lanthanide elements