Examples: The p-Block Elements

Introduction

A p-block element is one in which the last electron occupies a p-orbital and is in groups 3-18 (except Helium).” The elements of the p-block are divided into six groups because their orbitals can accommodate a total of six electrons. They have the configuration of ns2 np1-6.

Properties and Uses

• The number of electrons in the valence shell of p-block elements is 2/ 8/ 18
• These elements show covalency, whereas the higher members show electrovalency
• These elements show the phenomenon of allotropy. C, Si, P, S, B, Ge, Sn, As, etc., show this phenomenon
• Borax (a compound of Boron) is used in the pottery and glassmaking industry
• Iodine is used in the tincture of iodine
• Chlorine is used in disinfectants but is biologically toxic

Elements 

•  The Boron Family

Boron (B)

• Z=5 (group 13)
• It is a metalloid

Properties

• Bad conductor of electricity
• Boron salts emit a green colour when heated
• Its amorphous state is reactive

Use

• Bleach
• Antiseptics, eye drops, washing powders
• Nutritional supplements to improve joint and bone health

Aluminium (Al)

• Z=13
• A weak metal
• It has a high chemical affinity for oxygen, therefore, protects the metal from further corrosion by oxygen, water, or dilute acid, a process called passivation
• It has toxic biological effects

Gallium (Ga) 

• Z=31
• Not found in nature, obtained through the process of smelting
• Highly anisotropic
• They are used as semiconductors, cable television transmission, power electronics, commercial wireless infrastructure, and satellites
• It has biological importance in the treatment of cancer and inflammatory disorders

 Indium (In)

• Z=49
• Has toxic biologic effects and exposure can be through ingestion, inhalation, or absorption
• Used as vacuum seal wires to protect engines from corrosion in alkaline batteries

Thallium (Tl) 

•  Z= 81
• Highly toxic, called ‘Murder weapon,’ “the poisoner’s poison,” and “inheritance powder”
• Used as rat poison and ant killer, IR optics

•  The Carbon Family

Carbon (C)

• Z= 6
• Various allotropic forms such as Graphite, diamond, Fullerenes
• Uses- fossil fuel, methane gas, crude oil, lead for pencils, batteries       

 Silicon (Si)

• Z=14
• Low conductivity, reactivity, and toxicity
• Used to make ceramics, bricks, semiconductors, Portland cement

Germanium (Ge)

• Z=32
• Improve the immune system of cancer patients
• Used in transistors, fibre optics, and transistors 

Tin (Sn)

• Z=50
• It is soft, malleable, ductile, and highly crystalline metal

Lead (Pb)

• Z=82
• It is malleable, ductile, dense, and a poor conductor
• Used in ammunition, paints, pipes, batteries

• The Nitrogen Family

Nitrogen (N)     

• Z=7
• Also called Pnictogens
• Generally inert, nonmetallic, colourless, odourless, and tasteless
• It is used to make fertilisers, explosives, dyes, nylon, and nitric acid

Phosporous (P)

• Z=15
• In biological molecules such as ATP, ADP, and DNA. Found in the minerals in our bones and teeth
• It can cause severe skin burns since it is a poisonous waxy solid

Arsenic (As)

• Z=33
• It is a shiny, grey, brittle, metallic-looking solid
• Used as a doping agent in semiconductors to make special glass and preserve the wood

Antimony (Sb)

• Z=51
• It is a brittle, shiny, bluish-white solid having a flaky surface
• Used to increase the hardness of alloys in the automotive clutch and brake parts

Bismuth (Bi)

• Z=83
• Non-radioactive, hard, brittle, low melting point
• Used in making medicines, cosmetics, fire extinguishers, bullets

• The Oxygen Family

Oxygen

• Z=8
• A colourless, odourless, tasteless gas. Responsible for rusting of iron
• Used for artificial respiration in hospitals, steel production, brazing, welding, and cutting of other metals

Sulphur (S)

• Z=16
• It is tasteless and a brittle solid, Pale yellow, and a poor conductor of electricity
• Used in the vulcanization of black rubber, as an antifungal, and in black gunpowder 

• The Halogen Family

Fluorine (F)

• Z=9
• Gas at room temperature, most electronegative elements reactive non-metal
• Has its importance in dental health, making plastics, etch glass, and insulation of electric towers

Chlorine (Cl)

• Z=17
• It is an irritation-causing greenish-yellow gas, toxic to the eyes and respiratory system
• Used to disinfect water in the sanitation process

Bromine (Br)

• Z= 35
• Only element liquid at room temperature, dense, reddish-brownish liquid which evaporates easily at room temperature with a strong odour
• It is used in chemicals, dyestuffs, insecticides, pharmaceuticals, and chemical intermediates 

Iodine (I)

• Z=53
• It is a dark grey solid with a slight metallic lustre
• Used in medical treatment as tincture and iodoform, Promoting thyroid health, Improving birth weight

• The Noble Gases

Helium (He)

• Z= 2
• It is colourless, odourless, and tasteless
• It has a very low boiling point and is monatomic
• Used as an inert shield for arc welding, pressurising liquid-fueled rocket fuel tanks, and inflating balloons

Neon (Ne)

• Z=10
• It is a colourless, tasteless odourless inert gas, chemically inactive
• Used in wave metre tubes, vacuum tubes, and high voltage indicators

Argon (Ar)

• Z=18
• Third-Most abundant gas in earth’s atmosphere (0.93%).
• It is colourless, odourless, non-flammable, and non-toxic solid, liquid, or gas

Conclusion

Elements belonging to groups 13 to 18 of the periodic table are called the p-block elements. Their general configuration is ns2np1-6. The ionic radii increase down the group. There is an increase in covalent radii from N to P. The ionization energy decreases down the group as the atomic number increases. The boron group in group 13 of the periodic table comprises boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl). The carbon group of group 14 consists of carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl). The Nitrogen group of Group 15 consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and moscovium (Mc). The Chalcogens(Oxygen group) of group 16 consists of oxygen (O), sulfur (S), selenium (Se), tellurium (Te), polonium (Po), and livermorium (Lv). The Halogens of group 17 contain fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). The Noble gas Group of group 18 consists of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).