Element 56 of Periodic table is Barium with atomic number 56, atomic weight 137.327. Barium, symbol Ba, has a Body Centered Cubic structure and Silver color. Barium is a alkaline earth metal element. Trivial name of Barium is alkaline earth metals*. Know everything about Barium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Because of its high chemical reactivity barium is never found in nature as a free element.
Read key information and facts about element Barium
Name | Barium |
Atomic Number | 56 |
Atomic Symbol | Ba |
Atomic Weight | 137.327 |
Phase | Solid |
Color | Silver |
Classification | alkaline earth metal |
Group in Periodic Table | 2 |
Group Name | beryllium family |
Period in Periodic Table | 6 |
Block in Periodic Table | s-block |
Electronic Configuration | [Xe] 6s2 |
Melting Point | 727 °C |
Boiling Point | 1870 °C |
Electronic Shell Structure | [2, 8, 18, 18, 8, 2] |
CAS Number | CAS7440-39-3 |
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 56 to find Barium 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 Barium on periodic table look for cross section of group 2 and period 6 in the modern periodic table.
The element Barium was discovered by Carl Wilhelm Scheele in year 1808 in United Kingdom . Barium derived its name from the Greek barys, meaning 'heavy'
The table below shows the abundance of Barium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
Ppb by weight (1ppb =10^-7 %) | |
---|---|
Abundance in Universe | 1×10-6% |
Abundance in Sun | 1×10-6% |
Abundance in Meteorites | 2.7e-06 |
Abundance in Earth's Crust | 0.00034 |
Abundance in Oceans | 3×10-6% |
Abundance in Humans | 3e-07 |
The solid state structure of Barium is Body 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.
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)
a | b | c |
---|---|---|
502.8 | 502.8 | 502.8 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
π/2 | π/2 | π/2 |
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 | Im_ 3m |
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Space Group Number | 229 | |
Crystal Structure | Body Centered Cubic |
Barium atoms have 56 electrons and the electronic shell structure is [2, 8, 18, 18, 8, 2] with Atomic Term Symbol (Quantum Numbers) 1S0.
Atomic Number | 56 |
Number of Electrons (with no charge) | 56 |
Number of Protons | 56 |
Mass Number | 137 |
Number of Neutrons | 81 |
Shell structure (Electrons per energy level) | [2, 8, 18, 18, 8, 2] |
Electron Configuration | [Xe] 6s2 |
Valence Electrons | 6s2 |
Oxidation State | 1;2 |
Atomic Term Symbol (Quantum Numbers) | 1S0 |
Shell Structure of Barium - Electrons per energy level
n | s | p | d | f | |
---|---|---|---|---|---|
1 | K | 2 | |||
2 | L | 2 | 6 | ||
3 | M | 2 | 6 | 10 | |
4 | N | 2 | 6 | 10 | |
5 | O | 2 | 6 | ||
6 | P | 2 |
The ground state electronic configuration of Neutral Barium atom is [Xe] 6s2. The portion of Barium 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, electrons in the outermost shell that determine the chemical properties of the element.
Complete ground state electronic configuration for the Barium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 6s2
Barium atomic radius is 253 pm, while it's covalent radius is 198 pm.
Atomic Radius |
253 pm (2.53 Å) |
Atomic Volume | 39.1245014245 cm3 |
Covalent Radius | 198 pm (1.98 Å) |
Van der Waals Radius | N/A |
Neutron Cross Section | 1.3 σa/barns |
The electron affinity of Barium is 13.95 kJ/mol
Valence | 2 |
Electronegativity | 0.89 |
ElectronAffinity | 13.95 kJ/mol |
Refer to table below for Ionization energies of Barium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1 | 502.9 |
2 | 965.2 |
3 | 3.6×103 |
Refer to below table for Barium Physical Properties
Density | 3.51 g/cm3 |
Molar Volume | 39.1245014245 cm3 |
Young Modulus | 13 GPa |
Shear Modulus | 4.9 GPa |
Bulk Modulus | 9.6 GPa |
Poisson Ratio | N/A |
Mohs Hardness | 1.25 MPa |
Vickers Hardness | N/A |
Brinell Hardness | N/A |
Barium is Conductor of electricity. Refer to table below for the Electrical properties of Barium
Electrical Conductivity | 2.9×106 S/m |
Resistivity | 3.5×10-7 m Ω |
Superconducting Point | N/A |
Thermal Conductivity | 18 W/(m K) |
Thermal Expansion | 0.0000206 K-1 |
Magnetic Type | Paramagnetic |
Curie Point | N/A |
Mass Magnetic Susceptibility | 1.13×10-8 |
Molar Magnetic Susceptibility | 1.552×10-9 |
Volume Magnetic Susceptibility | 3.966e-05 |
Refractive Index | N/A |
Speed of Sound | 1620 m/s |
Refer to table below for Thermal properties of Barium
Melting Point | 1×103 K (727 °C) |
Boiling Point | 2143 K (1870 °C) |
Critical Temperature | N/A |
Superconducting Point | N/A |
Heat of Fusion | 8 kJ/mol |
Heat of Vaporization | 140 kJ/mol |
Heat of Combustion | N/A |
Isotopes of rhodium. Naturally occurring Barium has 7 stable isotope - 130Ba, 132Ba, 134Ba, 135Ba, 136Ba, 137Ba, 138Ba.
Isotope | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|
114Ba | ||||
115Ba | ||||
116Ba | ||||
117Ba | ||||
118Ba | ||||
119Ba | ||||
120Ba | ||||
121Ba | ||||
122Ba | ||||
123Ba | ||||
124Ba | ||||
125Ba | ||||
126Ba | ||||
127Ba | ||||
128Ba | ||||
129Ba | ||||
130Ba | 0.106% | Stable | N/A | |
131Ba | ||||
132Ba | 0.101% | Stable | N/A | |
133Ba | ||||
134Ba | 2.417% | Stable | N/A | |
135Ba | 6.592% | Stable | N/A | |
136Ba | 7.854% | Stable | N/A | |
137Ba | 11.232% | Stable | N/A | |
138Ba | 71.698% | Stable | N/A | |
139Ba | ||||
140Ba | ||||
141Ba | ||||
142Ba | ||||
143Ba | ||||
144Ba | ||||
145Ba | ||||
146Ba | ||||
147Ba | ||||
148Ba | ||||
149Ba | ||||
150Ba | ||||
151Ba | ||||
152Ba | ||||
153Ba |
CAS Number | CAS7440-39-3 |
RTECS Number | RTECSCQ8370000 |
DOT Hazard Class | 4.3 |
DOT Numbers | 1400 |
EU Number | N/A |
NFPA Fire Rating | 1 |
NFPA Hazards | Water Reactive |
NFPA Health Rating | 2 |
NFPA Reactivity Rating | 2 |
Autoignition Point | N/A |
Flashpoint | N/A |
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7440-39-3 |
CID Number | CID5355457 |
Gmelin Number | N/A |
NSC Number | N/A |
RTECS Number | RTECSCQ8370000 |
Metalloid |
Nonmetals |
Other Nonmetals | |
Halogens | Noble Gas |
Metals |
|
Alkali Metals | Alkaline Earth Metals |
Transition Metals | Post-Transition Metals |
Lanthanide | Actinide |