Question

Which of the following is NOT a property of phosphorus, according to the classifications of types of elements? A. Brittle in the solid state B. Poor electrical conductivity C. Does not show much luster D. Is generally malleable

Short answer

D. Is generally malleable

Step-by-step solution

Understand the Properties of Phosphorus

First, recognize that phosphorus is a non-metal. Non-metals have specific properties.

Identify Characteristics of Non-metals

Non-metals are generally brittle in the solid state, exhibit poor electrical conductivity, and do not show much luster.

Compare Given Options with Non-metal Properties

Review the given options and compare them with the properties of non-metals. Options A (Brittle in the solid state), B (Poor electrical conductivity), and C (Does not show much luster) are all properties of non-metals. Option D states 'Is generally malleable,' which is a property of metals, not non-metals.

Conclude the Incorrect Property

Determine that 'Is generally malleable' is not a property of phosphorus because phosphorus is a non-metal and non-metals are not malleable.

Key concepts

Non-metals

Phosphorus is an example of a non-metal. Non-metals are elements that typically lack the properties associated with metals. Instead of being shiny and good conductors of heat and electricity like metals, non-metals tend to have different characteristics that distinguish them.
Non-metals can be found in various states at room temperature. For instance, they can exist as gases (like oxygen), liquids (like bromine), or solids (like sulfur).
In general, non-metals are not malleable or ductile; they cannot be shaped or stretched into wires.
Instead, they tend to be brittle if they are in the solid state.
Additionally, non-metals have a high ionization energy and electronegativity, which means they easily attract electrons.

• They are poor conductors of heat and electricity.
• They usually have lower densities compared to metals.
• They often have higher electronegativity and ionization energies.

Therefore, the properties of phosphorus align with the typical characteristics of non-metals.

Brittleness

Brittleness is a key property of many non-metals including phosphorus. When we say a material is brittle, we mean it can break or shatter easily when subjected to stress.
This is the opposite of being malleable, where a material can be hammered or bent without breaking. Brittle materials, like phosphorus in its solid form, do not deform much before breaking. Instead, they tend to fracture.
This is because the atoms in brittle materials do not slide past each other easily under stress.
Instead, they are more likely to crack or break when a force is applied. Many non-metals, including phosphorus, exhibit brittleness because of their structure and bonding properties.

• Phosphorus, like other brittle non-metals, cannot be rolled into sheets or drawn into wires.
• It is more prone to breaking rather than bending when force is applied.

This makes brittleness an important feature to identify non-metals.

Electrical Conductivity

Electrical conductivity refers to a material's ability to conduct electric current. Metals are known for their excellent conductivity; however, non-metals, including phosphorus, are poor conductors.
This means that they do not allow electricity to flow through them easily. Phosphorus has a structure that does not support free movement of electrons, leading to poor conductivity.

• In metals, free electrons move easily, creating electrical current.
• In non-metals, the electrons are more tightly bound to their atoms and do not move as freely.

Poor electrical conductivity in non-metals such as phosphorus means they are often used as insulators in various applications.
Understanding this property helps in distinguishing between non-metals and metals.

Luster

Luster describes how shiny a material appears when light reflects from its surface. Most metals have a distinct shiny luster that makes them look bright and reflective. In contrast, non-metals usually lack this shiny appearance.
Phosphorus is one such non-metal that does not exhibit much luster. Instead of being shiny, it has a more dull or matte appearance.

• Shiny surfaces of metals are due to the presence of free electrons that reflect light.
• Non-metals do not have free electrons that reflect light in the same way, leading to a lack of luster.

This lack of luster can help differentiate non-metals like phosphorus from metals.
Recognizing these visual properties aids in quickly identifying the type of element you are dealing with.