Question

Select the member of group \(4 \mathrm{~A}\) that best fits each description: (a) forms chains to the greatest extent, (b) forms the most basic oxide, (c) is a metalloid that can form \(2+\) ions.

Short answer

(a) Carbon (C) forms chains to the greatest extent (b) Lead (Pb) forms the most basic oxide (c) Germanium (Ge) is the metalloid that can form 2+ ions

Step-by-step solution

(Step 1: Identify the elements in Group 4A)

Group 4A of the periodic table consist of Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), and Lead (Pb).

(Step 2: Analyze the element that forms chains to the greatest extent)

Carbon (C) forms chains to the greatest extent due to its ability to form strong covalent bonds with itself and other atoms. This ability to form long chains and complex structures is the basis for organic chemistry, where carbon is the central component of countless molecules found in living organisms.

(Step 3: Analyze the element that forms the most basic oxide)

The basicity of an oxide generally increases with increasing atomic number within a group in the Periodic Table. In Group 4A, Lead (Pb) is the element that forms the most basic oxide, which is the lead(II) oxide (PbO).

(Step 4: Analyze the metalloid that can form 2+ ions)

A metalloid is an element that exhibits both metallic and non-metallic properties. In Group 4A, Germanium (Ge) is the metalloid that can form 2+ ions, particularly in germanium(II) compounds like Germanium(II) Chloride (GeCl2). So, the correct answers for the given descriptions are: - (a) Carbon (C) forms chains to the greatest extent - (b) Lead (Pb) forms the most basic oxide - (c) Germanium (Ge) is the metalloid that can form 2+ ions

Key concepts

Carbon Chains in Organic Chemistry

Carbon forms the backbone of organic chemistry by creating an immense variety of structures. Its ability to form four bonds gives it the unique potential to construct long chains and complex three-dimensional figures that are crucial to the molecules of life. Carbon chains are fundamental in the development of compounds ranging from simple hydrocarbons to vast biomolecules.

The versatility of carbon lies in its tetravalency, meaning it has four electrons available for covalent bonding. Through the linkage of carbon atoms in chains, which can be linear, branched, or even cyclic, the possibility of forming an almost infinite number of compounds arises. These structures serve as skeletons for functional groups—other atoms or clusters of atoms that confer specific properties to the compound.

Furthermore, the strength of the carbon-carbon bond is a key factor that enables these chains to be stable and resistant to breaking. This property is why carbon can form long continuous chains more extensively than any other element, earning its central role in organic chemistry.

Basicity of Oxides

Oxides are compounds that contain oxygen and one other element. In chemistry, the term 'basicity' refers to the ability of an oxide to react with acids to form salt and water. As we move down a group in the periodic table, the metallic character of the elements increases, thus the oxides become more basic in nature.

In the case of Group 4A elements, lead(II) oxide (PbO) is the most basic oxide. This is because lead has the largest atomic size and the lowest electronegativity in this group, which makes its oxide more willing to donate electron pairs to hydrogen ions in acids, forming salt and water.

Comparing Basicity

Besides lead oxide, other Group 4A oxides exhibit varying degrees of basicity. For example, carbon dioxide (CO2) is acidic rather than basic, and silicon dioxide (SiO2) is essentially neutral. This variation in oxide properties across the group is an excellent demonstration of periodic trends and the changing character of these elements.

Metalloid Properties and Ions

Metalloids are elements that straddle the border between metals and nonmetals on the periodic table, displaying a mix of their properties. Germanium (Ge) from Group 4A is a classic metalloid with its semi-metallic characteristics, capable of forming various types of bonds and ions, including 2+ charged ions.

In contrast to true metals, which tend to lose electrons easily to form cations, metalloids like germanium require more specific conditions to form such ions due to their intermediate electronegativity and ionization energies. Germanium, when it forms 2+ ions, often does so in the context of covalent or semi-covalent compounds, such as germanium(II) chloride (GeCl2).

Applications of Metalloid Ions

Metalloid ions, such as Ge2+, are not as common as their metal counterparts but play crucial roles in various applications including electronics, fiber optics, and as catalysts in specific chemical reactions. The nuanced behavior of metalloids like germanium forms a bridge between metals and nonmetals, enriching the diversity of chemical substances and their interactions.