The P Block Elements Group 13-14

1.0What are p-block Elements? 

The p-block elements definition involves groups 13 to 18 and include nonmetals, metalloids, and metals. They exhibit diverse characteristics, ranging from insulating properties to conducting electricity, and participate in a wide array of chemical reactions. This group's electron configurations involve filling of p orbitals, leading to distinct chemical behaviors compared to s-block and d-block elements. Learn group 13 and 14 characteristics in this article.

The p-block elements, groups 13 and 14 of the periodic table are characterized by their valence electron configuration, where the outermost electron occupies a p-orbital. Group 13 elements include boron, aluminum, gallium, indium, and thallium, while Group 14 elements comprise carbon, silicon, germanium, tin, and lead. These elements exhibit a variety of chemical properties and are involved in numerous industrial and biological processes. Let’s discuss characteristics of p block elements, group 13 and 14.

2.0Group 13 (Boron Group)

Group 13 elements, comprising boron, aluminum, gallium, indium, and thallium, share a valence shell configuration of three electrons. They exhibit a combination of metallic and non-metallic properties, forming trivalent cations.

• Boron (B): A metalloid, boron is commonly found in borax and boric acid. It forms covalent compounds and has unique properties, including its ability to act as an electron acceptor.
• Aluminum (Al): A lightweight metal, aluminum is extensively used in construction, aerospace, and packaging industries due to its corrosion resistance and strength-to-weight ratio.
• Gallium (Ga): A soft, silvery metal, gallium is notable for its low melting point, just above room temperature. It finds applications in semiconductors and medical imaging.
• Indium (In): Another soft, silvery metal, indium is used in electronics, particularly in the production of LCD screens and touchscreens due to its conductive properties.
• Thallium (Tl): A highly toxic metal, thallium has limited industrial use but finds applications in specialized electronics and medical diagnostics.

3.0Inert Pair Effect

The inert pair effect refers to the tendency of heavier main group elements to preferentially retain their valence.

s electrons in their outermost shell rather than participating in chemical bonding. Specifically, elements in groups 13, 14, 15, and 16 of the periodic table exhibit this phenomenon.

For example, in Group 13, elements such as aluminum (Al) and gallium (Ga) primarily exhibit a +3 oxidation state, losing all three of their valence electrons. However, as we move down the group, heavier elements like indium (In) and thallium (Tl) tend to exhibit a preference for the +1 oxidation state, retaining their s electrons and forming compounds where they are partially or fully reduced.

4.0Electronic Configuration and Oxidation State of Group 13

The general electronic configuration of p block elements (Group 13) is ns² np¹. This means that they have two electrons in the s orbital and one electron in the p orbital of their outermost shell.

Oxidation State of p block Elements (Group 13)

Regarding oxidation states, Group 13 elements typically exhibit a +3 oxidation state. This is because they tend to lose their three outermost electrons to achieve a stable electron configuration.

5.0General Trends in Group 13

Atomic Radii:

• The atomic radii generally decrease across the group from Boron to Thallium due to increased nuclear charge, resulting in stronger attraction between the nucleus and outermost electrons.

Ionization Enthalpy:

• Ionization enthalpy tends to decrease down the group due to the increase in atomic size and the shielding effect of inner electrons, making it easier to remove outer electrons.

Electronegativity:

• Electronegativity decreases down the group as atomic size increases and effective nuclear charge decreases, reducing the atom's ability to attract electrons.

Physical Properties:

• Boron is a metalloid with unusual properties, while aluminum, gallium, indium, and thallium are metals.
• The metals in this group are relatively soft and have low melting and boiling points compared to transition metals.
• These metals exhibit metallic luster and conductivity.

Chemical Properties:

• Boron is known for its covalent bonding and often acts as a Lewis acid.
• Aluminum is the most abundant metal in the Earth's crust and is highly reactive, forming a protective oxide layer on its surface.
• Gallium and indium are used in various electronic applications due to their semiconducting properties.
• Thallium compounds are toxic and have limited industrial use.

6.0Reactions of Boron Family

(i) Reactivity towards air:

• Boron: Unreactive in its crystalline form. Amorphous boron forms B₂O₃ upon heating in air.
• Aluminum: Forms a protective oxide layer (Al₂O₃) when heated. Reacts with dinitrogen to form nitrides.
• Oxides: Boron trioxide is acidic, aluminum and gallium oxides are amphoteric, while indium and thallium oxides are basic.

(ii) Reactivity towards acids and alkalies:

• Boron: Unreactive with acids and alkalies. Aluminum shows amphoteric behavior, dissolving in both.
• Aluminum: Reacts with dilute hydrochloric acid, liberating hydrogen. Concentrated nitric acid renders aluminum passive.
• Reacts with aqueous alkali to form sodium tetrahydroxoaluminate(III).

(iii) Reactivity towards halogens:

• Group 13 elements form trihalides (EX₃) with halogens, except for thallium and iodine.

7.0Compounds of Boron

• Boric Acid (H₃BO₃): Boric acid is a weak acid commonly found in the form of white crystalline powder or colorless crystals. It is widely used as an antiseptic, insecticide, and flame retardant. It is also utilized in the manufacturing of glass, ceramics, and as a component in some medicinal preparations. Here is an image-

• Borax (Na₂B₄O₇·10H₂O): Borax, also known as sodium borate, is a naturally occurring mineral salt. It is a white, crystalline solid that dissolves readily in water. Borax is used in various industrial applications, including as a cleaning agent, flux in welding, and as a precursor in the production of boric acid and other boron compounds. Here is an image-

• Boranes: Boranes are compounds composed of boron and hydrogen atoms. Examples include diborane (B₂H₆) and borane (BH₃). These compounds are highly reactive and are used as reducing agents and in organic synthesis.
• Borax Pentahydrate (Na₂B₄O₇·5H₂O): Borax pentahydrate is a hydrated form of borax with five water molecules associated with each formula unit. It is commonly used in laundry detergents, cosmetics, and as a buffer solution in biochemical laboratories.
• Sodium Metaborate (NaBO₂): Sodium metaborate is a salt of boric acid and sodium hydroxide. It is used in the manufacturing of ceramics, as a flux in metallurgy, and as a buffer in chemical analysis.

8.0Group 14 (Carbon Family)

Group 14 elements, also known as the Carbon Family, consist of carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). Here's an overview of these elements:

Carbon (C):

• Carbon is known for its versatility, forming the basis of organic chemistry with millions of known compounds.
• It exists in various allotropes, including graphite, diamond, and fullerenes.
• Carbon compounds are crucial for life, forming the backbone of biomolecules such as proteins, DNA, and carbohydrates.

Silicon (Si):

• Silicon is the second most abundant element in the Earth's crust after oxygen.
• It is a semiconductor and plays a vital role in electronics and solar cell production.
• Silicon dioxide (SiO₂) is the principal component of sand and quartz.

Germanium (Ge):

• Germanium is a metalloid with properties intermediate between those of metals and nonmetals.
• It was used in early semiconductor devices but has been largely replaced by silicon.
• Germanium compounds are still used in infrared optics and as catalysts.

Tin (Sn):

• Tin is a soft, malleable metal with a silvery-white appearance.
• It is used in alloys such as bronze and solder, as well as in the production of tin cans.
• Tin compounds have various industrial applications, including in the manufacture of ceramics and glass.

Lead (Pb):

• Lead is a dense, soft metal with low melting and boiling points.
• It has been used since ancient times in various applications, including plumbing, batteries, and ammunition.
• Due to its toxicity, lead usage is now heavily regulated, although it still finds limited use in certain industries.

9.0Trends in Group 14

The Carbon Family, comprising Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), and Lead (Pb), exhibits a range of properties:

Atomic Radii:

Atomic radii increase down the group due to the addition of electron shells.

Carbon has the smallest atomic radius, while lead has the largest.

Ionization Enthalpy:

Ionization enthalpy generally decreases down the group due to increased atomic size and shielding effect.

Carbon has the highest ionization enthalpy, while lead has the lowest.

Electronegativity:

Electronegativity decreases down the group due to increased atomic size and shielding.

Carbon is the most electronegative, while lead is the least.

Physical Properties of p block elements :

Carbon exists in various allotropes, including graphite (a conductor) and diamond (an insulator).

Silicon, germanium, and tin are metallic elements with increasing metallic character down the group.

Lead is a dense, soft metal with low melting and boiling points.

Chemical Properties Properties of p block elements :

Carbon forms strong covalent bonds and exhibits a wide variety of compounds due to its ability to catenate.

Silicon and germanium form covalent compounds and are used in semiconductor devices.

Tin forms both ionic and covalent compounds, and lead typically forms ionic compounds due to its low electronegativity.

10.0Electronic Configuration and Oxidation State

p block elements Electronic Configuration and Oxidation State of Carbon Family

The general electronic configuration of p block elements (Group 14, the Carbon Family) is ns² np², where n represents the valence shell.

For example:

• Carbon (C): 1s² 2s² 2p²
• Silicon (Si): 1s² 2s² 2p⁶ 3s² 3p²
• Germanium (Ge): 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p²
• Tin (Sn): 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p²
• Lead (Pb): 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p²

The oxidation states exhibited by Group 14 elements vary:

• Carbon typically exhibits oxidation states of -4 (in compounds like methane, CH₄) and +4 (in compounds like carbon dioxide, CO₂).
• Silicon primarily shows oxidation states of +4 (in compounds like silicon dioxide, SiO₂).
• Germanium predominantly displays oxidation states of +2 and +4.
• Tin shows oxidation states of +2 and +4 in compounds, but also +3 and +4 in some cases.
• Lead most commonly exhibits oxidation states of +2 and +4, but also +2, +3, and +4 in various compounds.

11.0Reactions of Carbon Family

1. Reactivity towards oxygen:

• All members of the carbon family, when heated in oxygen, form oxides.
• Oxides exist in two main types: monoxides (MO) and dioxides (MO₂).

2. Reactivity towards water:

• Carbon, silicon, and germanium are not affected by water.
• Tin decomposes steam to form dioxide and dihydrogen gas: 

Sn  +  2H₂O  →  SnO + 2H₂

3. Reactivity towards halogens:

• Carbon, silicon, germanium, tin, and lead can form halides of the formula MX₂ and MX₄ (where X = F, Cl, Br, I).
• Except for carbon, all other members react directly with halogens under suitable conditions to form halides.
• Most MX₄ halides are covalent in nature, with the central metal atom undergoing sp³ hybridization, resulting in a tetrahedral shape.

12.0Compounds of Carbon and Silicon

Important compounds of Carbon and Silicon include:

Carbon:

• Carbon dioxide (CO₂): A colorless and odorless gas, a byproduct of combustion and respiration, vital for photosynthesis.
• Methane (CH₄): The simplest hydrocarbon, a major component of natural gas.
• Ethylene (C₂H₄): A colorless, flammable gas used in the production of plastics and as a plant hormone.
• Ethanol (C₂H₅OH): A volatile, flammable liquid used as a solvent, fuel, and in alcoholic beverages.

Allotropes of Carbon:

Silicon:

• Silicon dioxide (SiO₂): Also known as silica, a major component of sand and quartz, used in glassmaking and as a semiconductor material.

• Silane (SiH₄): A colorless, flammable gas used in the production of silicon-containing compounds.
• Silicon carbide (SiC): A hard, crystalline compound used as an abrasive and in ceramic materials.
• Silicones: A group of synthetic polymers containing silicon, oxygen, carbon, and hydrogen, used in sealants, adhesives, lubricants, and medical applications.