As a p-subshell has three degenerate p-orbitals, each of which can accommodate two electrons, there are six groups of p-block elements in total. Because of their tendency to lose an electron, they are shiny and usually a good conductor of electricity and heat. Gallium is a metal that can melt in our hands. Silicon is an important component of glass, it is also one of the most important metalloids of the p-block group.
The last electron in a p-block element enters one of the three p-orbitals of its respective shell.
Group 14 elements – Carbon Family
The group 14 elements are the second group in the periodic table’s p-block. It is also known as the carbon group. Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), Lead (Pb), and Flerovium (Fl) are members of this group.
Electronic Configuration
The general electronic configuration of the group 14 elements is ns2 np2.
The outermost p orbitals of these elements contain two electrons. Because all of the elements in group 14 have four electrons in their outermost shell, their valency is four. They use these electrons in bond formation to achieve an octet configuration.
Oxidation States and Inert pair Effect
The general oxidation states of group 14 elements are +4, and +2. The tendency to form +2 ions increases as we move down the group. This is because of the inert pair effect. P-block elements exhibit this effect. This is explained by the inert pair effect. It is the absence of the s-orbital during bonding due to insufficient shielding of the intervening electrons.
Electrons fill the d and f orbitals of elements such as Sn and Pb. Because the d and f orbitals have poor shielding abilities, the nuclear charge that seeps through attracts the s orbital closer to the nucleus. As a result, the s-orbital is reluctant to bond, and only the p electrons are involved in bonding. As a result, Pb+4 is an excellent oxidizing agent.
Anomalous Behaviour of Carbon
Carbon differs from the other elements in the group due to its small size, high electronegativity, high ionization enthalpy, and lack of d-orbital in the Valance Shell.
Chemical Properties of Group 14 elements
- Covalent Radii: The radii of group 14 elements are smaller than those of group 13. The increase in the effective nuclear charge can explain this. The increase in radii from C to Si is significant, followed by a smaller increase in radii. This is due to poor shielding of the d and f orbitals, which increases the effective nuclear charge, causing the radii to be small.
- Ionization Enthalpy: Group 14 elements have higher ionization energy than group 13 elements. This can be attributed to physical size. The Ionization Enthalpy decreases as one moves down the group. From C to Si, there is a sharp decrease, followed by a nominal decrease. The following is the order: C > Si > Ge > Pb >Sn. Due to ineffective shielding of the d and f orbitals, Pb has a higher Ionization Enthalpy than Sn in this case.
- Electronegativity: Because of their small size, the elements in this group have slightly more electronegativity than the elements in group 13. The electronegativity values of elements ranging from Si to Pb are nearly identical.
Physical Properties of Group 14 elements
- Metallic Character: Due to their small size and high ionization enthalpy, group 14 elements are less electropositive than group 13. The metallic character grows stronger as you progress through the group. Sn and Pb are soft metals with low melting points, while C and Si are nonmetals and Ge is a metalloid.
- Melting and Boiling Points: Carbon, silicon, and germanium have extremely high melting and boiling points due to their extremely stable solid structures. Because of the inert pair effect, Sn and Pb have a lower melting point because only two bonds are formed instead of four. Carbon has a very high melting point. All of the elements in group-14 have a diamond-like lattice structure that is extremely stable in nature. These highly stable lattice structures are broken as a result of the melting process. As the size of the atoms increases, the melting point decreases down the group as the M-M bonds are reduced. Because tin and lead are metals, their melting points are significantly lower.
- Four Covalent Compounds: Four covalent compounds are those in which the four electrons in the valence shell actively participate in bonding. This property is shared by the majority of the elements in Group 14.
- Density: Density rises as the atomic number rises due to an increase in mass per unit volume down the group.
Some important Compounds formed by Group 14 Elements
Oxides of Group 14
MO and MO2 oxides are formed by group 14 elements. Lead can also form the oxide Pb3O4, which is a mixture of PbO and PbO2. CO is a neutral monoxide, GeO is basic, and SnO and PbO are amphoteric. C is sp hybridized in CO2. It differs from SiO2, which is sp3 hybridized Si. Each O atom in SiO2 is bonded to two Si bonds. As a result, SiO2 has a three-dimensional structure. This also attests to its high melting point. The acidic character of the dioxides decreases as one moves down the group.
Halides of Group 14
They combine to form MX4 tetrahalides. The central atom has been sp3 hybridized and has taken on a tetrahedral shape. Elements below carbon have empty d-orbitals, which allow them to back the bond with halogens. Dihalides are not formed by carbon. The dihalides have a bent shape and are sp2 hybridized.
Reactivity towards water: Water has no effect on carbon, silicon, or germanium. Tin reacts with steam to produce dioxide and dihydrogen gas. Water has no effect on lead, most likely due to the formation of a protective oxide film.
Uses of Oxides of the Carbon family
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Carbon monoxide
- Carbon monoxide is a very important industrial gas because it is used in the production of many organic and inorganic compounds.
- It is used to keep packaged meat fresh in modified atmosphere packaging systems.
- In high power infrared lasers, it is used as a lasing medium.
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Carbon dioxide
- Carbon dioxide is used in a variety of industries, including the oil, food, and chemical industries.
- It is used in the production of urea in a variety of chemical industries.
- It is used as a food additive in the food industry.
- It’s a chemical that’s found in fire extinguishers.
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Silicon dioxide
- Silica is primarily used in the manufacture of glass, which is used for windows, bottles, and other applications.
- It is a key component in sand casting, which is responsible for the production of a wide range of engineering components and other materials.
- It is a common additive in the food industry.
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Silicones
- In the automotive industry, it is used as a lubricant.
- In the coating of silica-based substrates, silicones are used.
- Because of its good spreading properties and low water solubility, it is used as an active compound in deformers.
Sample Questions
Question 1: What are p-block elements?
Answer:
The p-block is a region of the periodic table that includes columns IIIA to VIIIA but excludes helium. There are 35 p-block elements, each with valence electrons in the p orbital. The p-block elements are a diverse group of elements with a wide range of properties.
Question 2: Why are they called p-block elements?
Answer:
Their name comes from the fact that their valence electrons are in the p orbital. To distinguish them from the transformation sequence and internal transformation, these are frequently referred to as Standard Components.
Question 3: What is catenation?
Answer:
Catenation is the ability of an element to form covalent bonds with other atoms of the same element, resulting in the formation of an atom chain.
Question 4: Which group 14 element exhibits catenation?
Answer:
To a large extent, carbon exhibits the catenation property. Carbon atoms, for example, can combine to form long chains, branched chains, and closed rings.
Question 5: Why does carbon behave differently from other group 14 elements?
Answer:
Carbon differs from the other elements in the group due to its small size, high electronegativity, high ionization enthalpy, and lack of d-orbital in the Valance Shell.