Boron is a Metalloid chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in both the Solar system and the Earth's crust. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals.
It belongs to group 13 of the periodic table having trivial name triels, icosagens.
Read key information and facts about element Boron
|Group in Periodic Table||13|
|Group Name||boron family|
|Period in Periodic Table||period 2|
|Block in Periodic Table||p -block|
|Electronic Configuration||[He] 2s2 2p1|
|Electronic Shell Structure (Electrons per shell)||2, 3|
|Melting Point||2348 K|
|Boiling Point||4273 K|
How to Locate Boron 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 5 to find Boron 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 Boron on periodic table look for cross section of group 13 and period 2 in the modern periodic table.
The element Boron was discovered by L. Gay-Lussac and L.J. Thénard in year 1808 in France and United Kingdom. Boron was first isolated by H. Davy in 1808. Boron derived its name from borax, a mineral.
Radical boracique appears on the list of elements in Lavoisier's Traité Élémentaire de Chimie from 1789. On June 21, 1808, Lussac and Thénard announced a new element in sedative salt, Davy announced the isolation of a new substance from boracic acid on June 30.
Boron Presence: Abundance in Nature and Around Us
The table below shows the abundance of Boron 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||1||0.1|
|Abundance in Sun||2||0.2|
|Abundance in Meteorites||1600||3000|
|Abundance in Earth's Crust||8700||17000|
|Abundance in Oceans||4440||2500|
|Abundance in Humans||700||410|
Crystal Structure of Boron
The solid state structure of Boron is Simple Trigonal.
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)
|506 pm||506 pm||506 pm|
and the angles between them Lattice Angles (alpha, beta and gamma).
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||R_ 3m|
|Space Group Number||166|
|Crystal Structure||Simple Trigonal|
|Number of atoms per unit cell|
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Boron Atomic and Orbital Properties
Boron atoms have 5 electrons and the electronic shell structure is [2, 3] with Atomic Term Symbol (Quantum Numbers) 2P1/2.
|Number of Electrons (with no charge)||5|
|Number of Protons||5|
|Number of Neutrons||6|
|Shell structure (Electrons per energy level)||2, 3|
|Electron Configuration||[He] 2s2 2p1|
|Valence Electrons||2s2 2p1|
|Main Oxidation States||3|
|Oxidation States||-5, -1, 0, 1, 2, 3|
|Atomic Term Symbol (Quantum Numbers)||2P1/2|
Bohr Atomic Model of Boron - Electrons per energy level
Ground State Electronic Configuration of Boron - neutral Boron atom
Abbreviated electronic configuration of Boron
The ground state abbreviated electronic configuration of Neutral Boron atom is [He] 2s2 2p1. The portion of Boron configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [He]. 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 2s2 2p1, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Boron
Complete ground state electronic configuration for the Boron atom, Unabbreviated electronic configuration
1s2 2s2 2p1
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
Atomic Structure of Boron
Boron atomic radius is 87 pm, while it's covalent radius is 82 pm.
|Atomic Radius Calculated|
87 pm (0.87 Å)
|Atomic Radius Empirical|
85 pm (0.85 Å)
|Atomic Volume||4.3947 cm3/mol|
|Covalent Radius||82 pm (0.82 Å)|
|Van der Waals Radius||192 pm|
|Neutron Cross Section||755|
|Neutron Mass Absorption||2.4|
Atomic Spectrum of Boron
Boron Chemical Properties: Boron Ionization Energies and electron affinity
The electron affinity of Boron is 26.7 kJ/mol.
Ionization Energy of Boron
Refer to table below for Ionization energies of Boron
|Ionization energy number||Enthalpy - kJ/mol|
Boron Physical Properties
Refer to below table for Boron Physical Properties
|Density||2.46 g/cm3(when liquid at m.p density is $2.08 g/cm3)|
|Molar Volume||4.3947 cm3/mol|
|Bulk Modulus||320 GPa|
Hardness of Boron - Tests to Measure of Hardness of Element
|Mohs Hardness||9.3 MPa|
|Vickers Hardness||49000 MPa|
Boron Electrical Properties
Boron is Conductor of electricity. Refer to table below for the Electrical properties ofBoron
|Electrical Conductivity||0.0001 S/m|
|Resistivity||10000 m Ω|
Boron Heat and Conduction Properties
|Thermal Conductivity||27 W/(m K)|
|Thermal Expansion||0.000006 /K|
Boron Magnetic Properties
|Mass Magnetic Susceptibility||-8.7e-9 m3/kg|
|Molar Magnetic Susceptibility||-9.41e-11 m3/mol|
|Volume Magnetic Susceptibility||-0.0000214|
Optical Properties of Boron
Acoustic Properties of Boron
|Speed of Sound||16200 m/s|
Boron Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Boron
|Melting Point||2348 K (2074.85°C, 3766.7299999999996 °F)|
|Boiling Point||4273 K (3999.85°C, 7231.7300000000005 °F)|
Enthalpies of Boron
|Heat of Fusion||50 kJ/mol|
|Heat of Vaporization||507 kJ/mol|
|Heat of Combustion||-|
Boron Isotopes - Nuclear Properties of Boron
Boron has 14 isotopes, with between 6 and 19 nucleons. Boron has 2 stable naturally occuring isotopes.
Isotopes of Boron - Naturally occurring stable Isotopes: 10B, 11B.
|Isotope||Z||N||Isotope Mass||% Abundance||T half||Decay Mode|
Compare Boron with other elements
Compare Boron with all Group 13 elements
Compare Boron with all Period 2 elements
Compare Boron with all Metalloid elements
What is the electronic configuration of Boron?
The electronic configuration of Boron is 1s2 2s2 2p1.
What is the abbreviated electronic configuration of Boron?
The abbreviated electronic configuration of Boron is [He] 2s2 2p1. To form abbreviated notation of electronic configuration, the completely filled subshells are replaced by the noble gas of the preceding period in square brackets.
What is the symbol of Boron?
Symbol of Boron is B. Boron is a chemical element with symbol B and atomic number 5.
What is the position of Boron in the Periodic Table?
Boron is a chemical element with the symbol B and atomic number 5. Boron is the 5 element on the periodic table. It is located in group 13 and period 2 in the modern periodic table.
What is the atomic number of Boron?
The atomic number of Boron is 5.
What is the color of Boron?
Boron is of Black color.
Who discovered Boron?
The element Boron was discovered by L. Gay-Lussac and L.J. Thénard in year 1808 in France and United Kingdom. Boron was first isolated by H. Davy in 1808.
How many valence electrons does a Boron atom have?
Boron has 3 valence electrons. Boron has 5 electrons out of which 3 valence electrons are present in the 2s2 2p1 outer orbitals of atom.
What is the melting Point of Boron?
Melting Point of Boron is 2348 K.
What is the boiling Point of Boron?
Boiling Point of Boron is 4273 K.
What is the melting Point of Boron in Kelvin?
Melting Point of Boron in Kelvin is 2348 K.
What is the boiling Point of Boron in Kelvin?
Boiling Point of Boron in Kelvin is 4273 K.
What is the electronic configuration of Boron 5?
The electronic configuration of Boron will be 1s2 2s2 2p1.
How do you write the electron configuration for Boron?
The electronic configuration of Boron will be 1s2 2s2 2p1.