Chemicool

B

5

10.81
Boron
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
Name Boron Symbol B
atomic number 5 Atomic weight 10.81
Density @ 293 K 2.34 g/cm3 Atomic volume 4.6 cm3/mol
Group Non-Metal discovered 1808

States
state (s, l, g) s
melting point 2352.2 K boiling point 3923.2 K
Heat of fusion 50.20 kJ/mol Heat of vaporization 489.70 kJ/mol
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Energies
1st ionization energy 800.6 kJ/mole electronegativity 2.04
2nd ionization energy 2427 kJ/mole electron affinity 26.7 kJ/mole
3rd ionization energy 3659.7 kJ/mole Specific heat 1.02 J/gK
heat atomization 573 kJ/mole atoms

Oxidation & Electrons
Shells 2,3 electron configuration [He] 2s2 2p1
minimum oxidation number 0 maximum oxidation number 3
min. common oxidation no. 0 max. common oxidation no. 3
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Appearance & Characteristics
structure special: B12 icosahedra color black
uses borax, glass making(B2O3) toxicity
hardness 9.5 mohs characteristics B12 icosahedra; 3 forms

Reactions
reaction with air mild, w/ht = B2O3 reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 none
reaction with 6M NaOH none
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Other Forms
number of isotopes 2 hydride(s) B2H6 and many BxHy
oxide(s) B2O3 chloride(s) BCl3 and many BxCly

Radius
ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 85 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 41 pm
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Conductivity
thermal conductivity 27.4 J/m-sec-deg electrical conductivity 0 1/mohm-cm
polarizability 3 A^3

Abundance
source Na and Ca borates (misc) rel. abund. solar system 1.326 log
abundance earth's crust 1 log cost, pure 250 $/100g
cost, bulk $/100g
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