kids encyclopedia robot

Boron facts for kids

Kids Encyclopedia Facts
Quick facts for kids
Boron, 5B
Boron R105.jpg
boron (β-rhombohedral)
Boron
Pronunciation /ˈbɔərɒn/ (BOHR-on)
Allotropes α-, β-rhombohedral, β-tetragonal (and more)
Appearance black-brown
Standard atomic weight Ar, std(B) [10.80610.821] conventional: 10.81
Boron in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


B

Al
berylliumboroncarbon
Atomic number (Z) 5
Group group 13 (boron group)
Period period 2
Block   p
Electron configuration [He] 2s2 2p1
Electrons per shell 2, 3
Physical properties
Phase at STP solid
Melting point 2349 K ​(2076 °C, ​3769 °F)
Boiling point 4200 K ​(3927 °C, ​7101 °F)
Density when liquid (at m.p.) 2.08 g/cm3
Heat of fusion 50.2 kJ/mol
Heat of vaporization 508 kJ/mol
Molar heat capacity 11.087 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 2348 2562 2822 3141 3545 4072
Atomic properties
Oxidation states −5, −1, +1, +2, +3 (a mildly acidic oxide)
Electronegativity Pauling scale: 2.04
Ionization energies
  • 1st: 800.6 kJ/mol
  • 2nd: 2427.1 kJ/mol
  • 3rd: 3659.7 kJ/mol
  • (more)
Atomic radius empirical: 90 pm
Covalent radius 84±3 pm
Van der Waals radius 192 pm
Color lines in a spectral range
Spectral lines of boron
Other properties
Natural occurrence primordial
Crystal structure ​rhombohedral
Rhombohedral crystal structure for boron
Speed of sound thin rod 16,200 m/s (at 20 °C)
Thermal expansion β form: 5–7 µm/(m⋅K) (at 25 °C)
Thermal conductivity 27.4 W/(m⋅K)
Electrical resistivity ~106 Ω⋅m (at 20 °C)
Magnetic ordering diamagnetic
Molar magnetic susceptibility −6.7·10−6 cm3/mol
Mohs hardness ~9.5
CAS Number 7440-42-8
History
Discovery Joseph Louis Gay-Lussac and Louis Jacques Thénard (30 June 1808)
First isolation Humphry Davy (9 July 1808)
Main isotopes of boron
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
10B 20% stable
11B 80% stable
10B content may be as low as 19.1% and as high as 20.3% in natural samples. 11B is the remainder in such cases.
B,5
Boron in a tube

Boron is a chemical element. It has the chemical symbol B. It has the atomic number 5. It is a metalloid (it has properties of a metal and a non-metal). Much boron is found in chemical compounds in its ore borax. Boron is never found free in nature.

Two types of boron are found (allotropes). Amorphous boron is a brown powder and metallic (crystalline) boron is black and hard and a weak conductor at room temperature. Boron is the 5th element in the periodic table it is part of the earths surface Pure boron is used as a dopant (a substance added to semiconductors to change how it behaves with electricity) in the semiconductor industry. Chemical compounds of boron are important as to make strong materials not weigh very much, as nontoxic insecticides and preservatives, and for chemical synthesis.

Plants need boron in them to live. Very small amounts of boron are needed in animal's bodies so that they are very healthy. How it keeps animals healthy is not known in a lot of detail.

Boron was discovered by Sir Humphry Davy, an English chemist, in 1808.

Boron melts at 2075 °C (3767 °F), and boils at 4000 °C (7232 °F).

Images for kids

Black History Month on Kiddle
Famous African-American Architects:
Georgia Louise Harris Brown
Julian Abele
Norma Merrick Sklarek
William Sidney Pittman
kids search engine
Boron Facts for Kids. Kiddle Encyclopedia.