Problem 57 - A Complete Resource Book in Chemistry for JEE Main

Question

Liquefied metals contain (a) metal anions only (b) metal cations only (c) metal kernels and mobile electrons (d) metal atoms only

Step-by-Step Solution

Answer

(c) metal kernels and mobile electrons

Step 1: Understand the Context

When discussing metals, particularly in a liquefied state, it's important to understand the structure of metals. Metals are characterized by metallic bonding, where there is a lattice of metal cations and a 'sea' of delocalized electrons.

Step 2: Analyzing Metal Structure

In a metal, the metal atoms lose their valence electrons which results in positive ions or cations. These cations are arranged in a lattice structure, surrounded by a 'sea' of free, mobile electrons.

Step 3: Define the Given Options

We are evaluating the composition of liquefied metals based on the given options: - (a) Metal anions: Negatively charged ions, unlikely in metals. - (b) Metal cations: Positive ions present in a metal lattice. - (c) Metal kernels and mobile electrons: Likely describers of the structure, given the free electrons. - (d) Metal atoms: Not accurate as atoms in metals lose some electrons becoming cations.

Step 4: Determine the Correct Answer

Liquefied metals mainly contain metal kernels or cations surrounded by a sea of mobile electrons due to metallic bonding. This matches the description in option (c). Therefore, the composition includes metal kernels along with the mobility of electrons, characteristic of ionic behavior within metals.

Key Concepts

Liquefied Metals

When metals transition from a solid to a liquid state, their internal structure doesn't change drastically; they still maintain some core properties of metallic bonding. In a solid state, metals feature a lattice of metal cations surrounded by delocalized electrons. When these metals are heated to their melting point, they become liquefied. While the rigid lattice structure is disrupted, the metallic bonding remains.
Liquefied metals continue to exhibit unique properties due to this retained structure. This includes being excellent conductors of electricity due to free-moving electrons.
Remember that liquefied metals don't literally disassemble into individual atoms. The structural positive ions, usually metal cations, float within the continuum of delocalized electrons. These characteristics enable metals to remain functional in different states while retaining essential conductive properties.

Metal Cations

Metal cations are a key component in the structure of metallic bonds. As metals exist, their atoms naturally seek stability by losing electrons. By shedding these electrons, metal atoms transform into cations, which are positively charged ions.
The loss of electrons from the outer shell isn't a loss entirely to the environment; instead, these electrons become part of the electron sea. This process is crucial for metals to achieve a stable electron configuration, typically the one achieved by noble gases.
Metal cations are thus integral to metallic structures as they allow the metal to sustain the properties of strength, ductility, and thermal as well as electrical conductivity. In every metal, whether solid or liquid, these cations are aligned in a lattice, surrounded by free electrons that shore up their properties.

Delocalized Electrons

Delocalized electrons play a pivotal role in the concept of metallic bonding. They are essentially the electrons not bound to any single atom or ion. These electrons originate from the outer shell of metal atoms when they transform into cations. Once freed, they move throughout the metallic structure, creating what is often described as a 'sea' of electrons surrounding the positively charged metal ions.
These electrons are essential for both conductivity and the overall integrity of metals. Thanks to this freedom of movement, delocalized electrons enable metals to be excellent conductors of electricity and heat.
They are also responsible for the malleability and ductility seen in metals, allowing them to be reshaped without breaking their internal structure. Overall, delocalized electrons contribute significantly to the characteristic properties that make metals so useful in various industrial and practical applications.