Question

Which of the following metals is soft in nature? (a) platinum (b) iron (c) aluminium (d) sodium

Short answer

a) Platinum b) Iron c) Aluminium d) Sodium Answer: d) Sodium

Step-by-step solution

Platinum:

Platinum is a precious metal with a shiny, silvery appearance. It is dense, malleable (can be hammered into thin sheets), and ductile (can be stretched into wires). However, it is not considered to be a soft metal.

Iron:

Iron is a lustrous, silvery-gray metal, and it is very common among metallic elements. It is strong, hard, and magnetic, making it ideal for use in construction and engineering applications. Iron is not a soft metal.

Aluminium:

Aluminium is a relatively soft, lightweight, and silvery-white metal. It has an excellent strength-to-weight ratio, which makes it ideal for many applications, including construction, transportation, and packaging industries. However, it is not as soft as some other metals.

Sodium:

Sodium is a soft, silvery-white, highly reactive alkali metal. Its softness allows it to be easily cut with a knife. Being highly reactive, it reacts quickly with water, so it is stored in mineral oil to prevent contact with air and moisture. Among the given options, sodium is the softest metal. Thus, the correct answer is (d) sodium.

Key concepts

Metal Properties

Metals are fascinating elements due to their unique set of properties. These include characteristics like conductivity, malleability, ductility, and luster. Conductivity refers to the ability of metals to conduct electricity and heat effectively.
Most metals, since they have free-flowing electrons, excel at this property. Malleability allows metals to be hammered or rolled into thin sheets without breaking, while ductility refers to their ability to be drawn into wires. Both properties are due to the metallic bonds where atoms are arranged in a lattice that can shift without breaking.
Another notable property is luster, which gives metals their shiny appearance because they reflect light well. While these common properties apply to most metals, each metal has its own specific set of characteristics influenced by its atomic structure and bonding.
Softness is one such property that varies significantly across different metals. For instance, softer metals, like sodium, can be cut with a simple tool, while others, such as iron, are much harder. Understanding these properties is crucial for determining the appropriate applications and potential uses of each metal.

Sodium

Sodium is best known as a soft, silvery-white metal in the alkali family of the periodic table. It ranks prominently due to its distinctive characteristics, particularly its softness and reactivity. Its soft nature means it can easily be cut with a knife, a trait not common among metals. because of its low melting point compared to many other metals, this softness is accompanied by traits like lightness and malleability.
In terms of applications, sodium is involved in a plethora of chemical processes. For example, it's crucial in synthesizing a variety of inorganic compounds like sodium chloride, which is table salt. In nature, sodium doesn't occur freely due to its reactivity but is found in compounds.
It's important to handle sodium carefully due to its reactivity, especially its ability to react vigorously when exposed to water. This property necessitates storing sodium in oil to prevent unwanted reactions that could be hazardous.

Reactivity of Metals

The reactivity of metals is an essential topic in chemistry that explores how metals interact with other substances. Reactivity in metals is primarily determined by their ability to lose electrons and form positive ions, or cations. The more easily a metal loses electrons, the more reactive it is. Alkali metals, like sodium, are considered highly reactive. They readily react with water, oxygen, and other elements.
The reactivity series is a helpful tool that ranks metals based on their reactivity from most reactive, like potassium and sodium, to less reactive, such as gold and platinum. This series helps predict the outcomes of reactions involving metals and how they need to be handled. For instance, more reactive metals, such as sodium, are not freely found in nature due to their tendencies to form compounds readily.
These variations in reactivity determine essential factors such as durability, corrosion resistance, and necessary precautions for handling. Understanding metal reactivity is vital for their safe application and for exploiting their properties to enhance different chemical processes.