Boron

Boron is a chemical element that belongs to metalloid group in modern periodic table. It is the fifth element in the periodic table and the first among the metalloids. It has atomic number 5 and is denoted by the symbol B. It was discovered by scientist Joseph Louis Gay-Lussac in 1808.

In this article, we will discuss the complete details about Boron including what is Boron, its uses, properties and many other important facts

Boron Element
Symbol	B
Atomic Number	5
Atomic Mass	10.811
Discovered by	Joseph Louis Gay-Lussac

What is Boron?

Boron is a light chemical element which is placed in period 2, group 13 and the p-block of periodic table. The chemical symbol of Boron is “B”. The atomic number of Boron is 5. The nucleus of this atom consists of six neutrons and five positively charged protons and five electrons. In its crystalline form Boron is dark in color, brittle and shiny; on the other hand in its amorphous form Boron is found as brown powder. Elemental boron is a metalloid that is found in the crust of earth. It has two naturally occurring and stable isotopes that are-

• ¹¹B (80.1%)
• ¹⁰B (19.9%).

Boron Symbol

The symbol of Boron element is shown in the picture below:

Boron Element Details

The detailed data of Boron is discussed below:

Subjects	Details
Symbol	B
Group	13
Period	2
Family Group	Metalloid
Atomic Number	5
Atomic Mass	10.811
Block	p
Electronic Configuration	[He] 2s2 2p1
Electrons Per Shell	2,3
Melting Point	2349K (2036℃)
Boiling point	4200K (3927℃)
Key Isotopes	10B, 11B
Density	2.08g/cm3 (at melting point)
Molar Heat Capacity	11.087 J/(mol·K)
Oxidation States	-5, -1, 0, +1, +2, +3(an oxide mildly acidic)
Electronegativity	Pauling Scale: 2.04
Atomic Radius	Empirical: 90 pm
Covalent Radius	84±3 pm
Van der Waals Radius	192 pm
Natural Occurrence	Primordial
Crystal Structure	​Rhombohedral
Thermal expansion	at 25℃ – β form: 5–7 µm/(m⋅K)
Thermal conductivity	27.4 W/(m⋅K)
Magnetic ordering	Diamagnetic

Properties of Boron

The properties of Boron are classified into two categories. These are:

• Physical Properties of Boron
• Chemical Properties of Boron

Physical Properties of Boron

Boron has several physical properties. These physical properties are:

• The melting point of boron is 2349K and boiling point is 4200K
• The atomic mass of boron is 10.811 u and atomic number is 5
• The Electronic configuration of boron is [He]2s²2p¹
• It has a high melting point because of the very strong crystal lattice
• In its crystalline form Boron is dark in color
• Molar Heat Capacity of Boron is 11.087J/(mol‧K)
• At STP(standard temperature and pressure) Boron has Solid state.

Chemical Properties of Boron

The chemical properties of Boron are as follows:

• At room temperature boron does not react with air, but at high temperature it burns to form Boron Trioxide:

4B + 3O₂ → 2B₂O₃

• When boron undergoes halogenation, it produces Trihalides. The reaction is given below

2B + 3Br₂ → 2BBr₃

• Boron has two naturally and stable isotopes – ¹¹B & ¹⁰B
• The amorphous form of boron is non-reactive to oxygen, water, acid and alkalis.
• Boron is a poor conductor of electricity.

Uses of Boron

Borazine, borates, boron citrate, boric acid etc. are important compounds of boron which are useful in industries, medical fields and pharmacies. Some of the uses of boron are discussed bellow:

Industrial Use of Boron

Boron has many industrial uses, they are as following:

• Boron compounds are important ingredients in textile industries.
• It is also used to make heat resistant glasses and fiberglass.
• Boron in the form of orthoboric acid is used to make cosmetic items.
• Some of the isotopes of boron are used in nuclear reactors for controlling nuclear reactions because they are good in absorbing neutrons. Boron in its amorphous form is used as a fuel igniter in rockets.
• Boron compound borates are used in washing powder as brighteners. It is also a bleaching agent.
• Boron compound borax is used as alkali in the photographic developers and an important compound for the paint industry also.
• Boron is used in batteries to improve its battery life, performance, efficiency etc.

Pharmaceutical Uses of Boron

Boron has a few pharmaceutical uses like producing heat resistant glasses useful in laboratories to, chemicals like fertilizers etc.

• Boron in the form of Borax or sodium borate is used to kill small insects like ants, so it is also used in agricultural field to produce liquid fertilizers.
• It is used to make antiseptic for treatment of minor burns.
• Borax is used to remove the permanent and temporary hardness of water.
• It is used in making borosil glasses, and other heat resisting glasses for laboratories.
• Borax is used as a buffering agent to control the pH level of water in swimming polls.
• A large number of people uses eye drops and eye wash to keep their vision healthy and seek relief from discomfort. When applied in small quantities, boric acid controls pH, and provides relief from eye irritations.

Medical Uses of Boron

Boron has several medical uses, which are discussed below:

• It is useful in the treatment of bacterial infection of horses.
• In medical fields, boron is used for the treatment of some kind of brain tumor. Boron medicine helps in building strong bones in human body. It also helps in keeping cell wall healthy in plants.
• Borax is used in the treatment of fungal foot disease.
• Borax is a common element in commercially available vitamin supplements.

Other Uses of Boron

Boron has several other uses, which are useful in our daily life. Some of these uses are discussed below:

• Boron in the form of orthoboric acid is used to preserve food items like fish, milk, breads, and other food items.
• Boron works as a wood preservative as it helps to make wood fireproof.

Facts About Boron

The interesting fact about boron is mentioned below:

• The name Boron is taken from the Arabic word “Buraq“, by which the Arabians used to denote borax in the ancient times.
• If we discuss about the sources of boron, It is a rare element found in the crust of earth. It is naturally found in the compounds like borax and boric acid. Rasorite is considered the most important source of boron which is found mostly in California in USA.
• Boron in the form of boromycin is used to treat streptomyces, as it acts as a natural antibiotic.

Frequently Asked Questions on Boron

What are the key isotopes of boron?

The key isotopes of boron are ¹⁰B and ¹¹B.

What is the crystal structure of boron?

The crystal structure of boron is Rhombohedral.

Is boron a metal or nonmetal?

Boron is a Metalloid, which means it has both the metallic and non metallic properties. But due to its chemical behavior it is more closely associated with the nonmetals.

What is the phase of boron at STP?

At STP (standard temperature and pressure) Boron has Solid state.

Is boron found in India?

At present the deposit of borax is found in India in Puga Valley in Leh district of Jammu & Kashmir, Gujarat and Rajasthan.

What is the use of boron?

Boron has various types of uses, mostly in fiber-glasses, detergent, textile industries, semiconductor, nuclear reactors and in the health sector including the treatment of brain tumor, streptomyces, making antiseptic etc. It is also widely used to make fertilizers, cosmetic items, insecticides etc.

What is the main source of boron?

Rasorite is the main source of boron, which can be found in California of USA. It is also found in the minerals like borax, kernite, colemanite etc. and in the organic food and vegetables also such as milk, coffee, peanuts, broccoli, potatoes etc.

Is boron a poor metal?

Boron is a metalloid, not a poor metal. If we study its metallic properties, it has less density compared to metals, and it is a poor conductor of heat and electricity in room temperature, it is stable and is a very hard element.

Is boron strong or weak?

Yes, boron is a strong element. Its hardness is 9.3 on Mohs scale. Boron is used as a heat resistant and is very hard, for that reason boron filaments are widely used by the aerospace industries. Crystalline boron is the second hardest element after diamond.