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Mg Magnesium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

12
Mg
Magnesium
Element 12 of Periodic table is Magnesium with atomic number 12, atomic weight 24.305. Magnesium, symbol Mg, has a Simple Hexagonal structure and Silver color. Magnesium is a Alkaline Earth Metal element. It is part of group 2 (beryllium family). Know everything about Magnesium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
12 Mg - Magnesium | SchoolMyKids

Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (Group 2, or alkaline earth metals) of the periodic table:they each have the same electron configuration in their outer electron shell producing a similar crystal structure. Magnesium is the ninth most abundant element in the universe.

It belongs to group 2 of the periodic table having trivial name alkaline earth metals*.

Magnesium Facts

Read key information and facts about element Magnesium

NameMagnesium
Atomic Number12
Atomic SymbolMg
Atomic Weight24.305
PhaseSolid
ColorSilver
Appearanceshiny grey solid
ClassificationAlkaline Earth Metal
Group in Periodic Table2
Group Nameberyllium family
Period in Periodic Tableperiod 3
Block in Periodic Tables -block
Electronic Configuration[Ne] 3s2
Electronic Shell Structure (Electrons per shell)2, 8, 2
Melting Point923 K
Boiling Point1363 K
CAS NumberCAS7439-95-4
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 Magnesium 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 12 to find Magnesium 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 Magnesium on periodic table look for cross section of group 2 and period 3 in the modern periodic table.

Magnesium History

The element Magnesium was discovered by J. Black in year 1755 in United Kingdom. Magnesium was first isolated by H. Davy in 1808. Magnesium derived its name from Magnesia, a district of Eastern Thessaly in Greece.

Black observed that magnesia alba (MgO) was not quicklime(CaO). Davy isolated the metal electrochemically from magnesia.

Magnesium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Magnesium 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 Universe60000030000
Abundance in Sun70000030000
Abundance in Meteorites120000000100000000
Abundance in Earth's Crust2900000025000000
Abundance in Oceans1326000337000
Abundance in Humans27000070000

Crystal Structure of Magnesium

The solid state structure of Magnesium 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
320.94 pm320.94 pm521.08 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 12 Mg Magnesium - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number194
Crystal StructureSimple Hexagonal

Magnesium Atomic and Orbital Properties

Magnesium atoms have 12 electrons and the electronic shell structure is [2, 8, 2] with Atomic Term Symbol (Quantum Numbers) 1S0.

Atomic Number12
Number of Electrons (with no charge)12
Number of Protons12
Mass Number24
Number of Neutrons12
Shell structure (Electrons per energy level)2, 8, 2
Electron Configuration[Ne] 3s2
Valence Electrons3s2
Valence (Valency)2
Main Oxidation States2
Oxidation States0, 1, 2
Atomic Term Symbol (Quantum Numbers)1S0

Bohr Atomic Model of Magnesium - Electrons per energy level

12 Mg Magnesium - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Magnesium - neutral Magnesium atom

Abbreviated electronic configuration of Magnesium

The ground state abbreviated electronic configuration of Neutral Magnesium atom is [Ne] 3s2. The portion of Magnesium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ne]. 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 3s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Magnesium

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

1s2 2s2 2p6 3s2

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 Magnesium
    Atomic Structure of Magnesium

    Magnesium atomic radius is 145 pm, while it's covalent radius is 130 pm.

    Atomic Radius Calculated

    145 pm (1.45 Å)

    Atomic Radius Empirical

    150 pm (1.5 Å)

    Atomic Volume13.984 cm3/mol
    Covalent Radius130 pm (1.3 Å)
    Van der Waals Radius173 pm
    Neutron Cross Section0.063
    Neutron Mass Absorption 0.0001

    Atomic Spectrum of Magnesium

    Atomic Spectrum of Magnesium | SchoolMyKids

    Magnesium Chemical Properties: Magnesium Ionization Energies and electron affinity

    The electron affinity of Magnesium is 0 kJ/mol.

    Valence2
    Electronegativity1.31
    ElectronAffinity0 kJ/mol

    Ionization Energy of Magnesium

    Refer to table below for Ionization energies of Magnesium

    Ionization energy numberEnthalpy - kJ/mol
    1st737.7
    2nd1450.7
    3rd7732.7
    4th10542.5
    5th13630
    6th18020
    7th21711
    8th25661
    9th31653
    10th35458
    11th169988
    12th189368

    Magnesium Physical Properties

    Refer to below table for Magnesium Physical Properties

    Density1.738 g/cm3(when liquid at m.p density is $1.584 g/cm3)
    Molar Volume13.984 cm3/mol

    Elastic Properties

    Young Modulus45
    Shear Modulus17 GPa
    Bulk Modulus 45 GPa
    Poisson Ratio0.29

    Hardness of Magnesium - Tests to Measure of Hardness of Element

    Mohs Hardness2.5 MPa
    Vickers Hardness-
    Brinell Hardness260 MPa

    Magnesium Electrical Properties

    Magnesium is Conductor of electricity. Refer to table below for the Electrical properties ofMagnesium

    Electrical Conductivity23000000 S/m
    Resistivity4.4e-8 m Ω
    Superconducting Point-

    Magnesium Heat and Conduction Properties

    Thermal Conductivity160 W/(m K)
    Thermal Expansion0.0000082 /K

    Magnesium Magnetic Properties

    Magnetic TypeParamagnetic
    Curie Point-
    Mass Magnetic Susceptibility6.9e-9 m3/kg
    Molar Magnetic Susceptibility1.68e-10 m3/mol
    Volume Magnetic Susceptibility0.000012

    Optical Properties of Magnesium

    Refractive Index-

    Acoustic Properties of Magnesium

    Speed of Sound4602 m/s

    Magnesium Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Magnesium

    Melting Point923 K (649.85°C, 1201.73 °F)
    Boiling Point1363 K (1089.85°C, 1993.73 °F)
    Critical Temperature-
    Superconducting Point-

    Enthalpies of Magnesium

    Heat of Fusion8.7 kJ/mol
    Heat of Vaporization128 kJ/mol
    Heat of Combustion-668 J/(kg K)

    Magnesium Isotopes - Nuclear Properties of Magnesium

    Magnesium has 22 isotopes, with between 19 and 40 nucleons. Magnesium has 3 stable naturally occuring isotopes.

    Isotopes of Magnesium - Naturally occurring stable Isotopes: 24Mg, 25Mg, 26Mg.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    19Mg12719Synthetic
    20Mg12820Synthetic
    21Mg12921Synthetic
    22Mg121022Synthetic
    23Mg121123Synthetic
    24Mg12122478.99%Stable
    25Mg12132510%StableN/A
    26Mg12142611.01%StableN/A
    27Mg121527Synthetic
    28Mg121628Synthetic
    29Mg121729Synthetic
    30Mg121830Synthetic
    31Mg121931Synthetic
    32Mg122032Synthetic
    33Mg122133Synthetic
    34Mg122234Synthetic
    35Mg122335Synthetic
    36Mg122436Synthetic
    37Mg122537Synthetic
    38Mg122638Synthetic
    39Mg122739Synthetic
    40Mg122840Synthetic

    Regulatory and Health - Health and Safety Parameters and Guidelines

    Database Search

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

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7439-95-4
    RTECS Number-
    CID Number CID5462224
    Gmelin Number-
    NSC Number-