The elements of the group 13 – 18 come under the p – block elements. In these elements the last electron enters in the outermost p – orbital. They have ns2np1-6 electronic configuration in valence shell, helium being an exception. These elements show the maximum oxidation state equal to the sum of electrons in the outermost shell or valence shell. Most of the elements of the p – block form covalent compounds although some elements form ionic compounds (such as halogens) and coordination compounds as well. p-block contains elements which are either metals, non – metals or metalloids. p-block elements include the group of halogens and inert gases. First member of each family of the p-block elements is given below in the table with their general electronic configuration and oxidation states. p-block has the most electronegative element which is fluorine. Elements of p-block generally form acidic oxides. Many elements such as C, Si, Ge, O, N etc. also show phenomena of allotropy. Property of catenation is also shown by many elements.
Group 13 is the first group of p-block elements. First element of this group is Boron which is the only metalloid of this group. This is the reason that group 13 is also known as boron family.
Important trends of group 13 elements are listed below –
Trichloride, Tribromides and Triiodides of group 13 elements are covalent in nature and can be hydrolyzed in water.
Monomeric trihalides of these elements are strong Lewis acids.
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Metal halides of group 13 elements are generally dimerized through halogen bonding.
Anomalous properties of Boron are listed below –
Boron shows quite higher melting and boiling points than other elements of group 13.
Boron forms only covalent compounds while other elements of the group 13 form both ionic and covalent compounds.
Boron is a metalloid while other elements of the group 13 are metals.
Oxides and hydroxides of boron are acidic in nature while oxides and hydroxides of other elements of the group are amphoteric and basic in nature.
Boron, aluminium and their compounds are of great importance biologically and environmentally. Few of their applications are listed below –
Boron fibers are used in the bullet proof jackets.
Boron is used in light composite material for aircrafts.
Boron compounds are used in glass making, borax beads test, jewelry industry, antiseptic.
Various boron compounds are used as rubber vulcanizer, rocket propellant, flame speed accelerator etc.
Aluminium is used in wires as it’s a good conductor of electricity.
Al is used in various utensils as well as it’s a good conductor of heat.
It is used in pipes, rods, tubes etc.
Al is used in many alloys of Zn, Mg, Cu, Mn etc.
Compounds of aluminium are used in manufacturing of rubber, pharmaceuticals, textiles and as pesticides, lubricants and wood preservatives.
Al compounds are used in preparation of many compounds.
Aluminium chloride is used as a catalyst in Friedel - Craft acylation reaction.
Group 14 is the second group of p-block elements. First element of this group is carbon which is found in large quantities in nature and the 7th most abundant element in the earth’s crust. This is the reason that group 14 is also known as carbon family. Apart from this carbon also shows various unique properties as well such as catenation etc. The branch of chemistry – Organic Chemistry is based on the carbon and its compounds.
Carbon differs from other members of the group 14. This is because of small size of carbon atom, higher electronegativity, higher ionization enthalpy, unavailability of the d-orbital and catenation property of carbon.
In carbon d – orbital is not available for bonding, only s and p orbitals are available for bonding. This is the reason it can accommodate only 4 pairs of electrons in bonding.
Carbon can form multiple bonds with another carbon atom and other atoms of other elements which possess high electronegativity and small size. For example, C=C, C=O, C=N etc. Carbon can form chain and ring compounds. It shows the property of catenation.
Many allotropes of carbon are found in nature due to its catenation property.
Many crystalline and amorphous allotropic forms of carbon are found in nature. The property of elements to exist in two or more different forms is called allotropy and the different forms are called allotropes of that element. Here, we are discussing three main allotropes of carbon in the table given below –
Uses of Carbon
Carbon is a very useful element. Organic chemistry is based on carbon and its compounds. Few of its uses are listed below –
Graphite is used in batteries and filaments due to its electricity conducting property.
Diamond is used in glass cutting.
Graphite is used in the pencils.
Graphite is used to make crucibles which are inert to acids and alkalies.
Graphite is used in tennis rackets, fishing rods, aircrafts etc.
Diamond is used in ornaments, polishing, lapping etc.
Oxides of carbon are of great importance and are found in nature. Here we are discussing two main oxides of carbon in the table below –
95% of the earth’s crust is composed of silica and silicates. Being a metalloid, it possesses some characteristics of metals and some of non – metals. That’s why it becomes of more use. Silicon forms many compounds which are of great use commercially. Here we are discussing three main compounds of silicon in the table below –
This ends our coverage on the summary of the unit “The p-block elements”. We hope you enjoyed learning and were able to grasp the concepts. You can get separate articles as well on various subtopics of this unit such as carbon family, elements of group 14 etc. on Vedantu website. We hope after reading this article you will be able to solve problems based on the topic. We have already provided detailed study notes or revision notes for this unit, which you can easily download by registering yourself on Vedantu website. Here in this article we have discussed the unit in a summarized way with the emphasis on important topics of the unit. If you are looking for solutions of NCERT Textbook problems based on this topic, then log on to Vedantu website or download Vedantu Learning App. By doing so, you will be able to access free PDFs of NCERT Solutions as well as Revision notes, Mock Tests and much more.