With the exception of helium, the noble gases condense to form solids when they are cooled sufficiently. At temperatures below 83 K, argon forms a close-packed solid whose structure is shown below. (b) Is this value larger or smaller than the bonding atomic radius estimated for argon in Figure 7.7?

Key Concepts

Noble Gases

Noble gases are a group of elements in Group 18 of the periodic table, known for their lack of reactivity due to having a full valence shell of electrons. They include helium, neon, argon, krypton, xenon, and radon. Understanding their unique properties, such as low boiling points and the ability to form solids at low temperatures, is essential for analyzing their behavior in different states of matter.

Bonding Atomic Radius

The bonding atomic radius is a measure of the size of an atom that is bonded to another atom, typically defined as half the distance between the nuclei of two bonded atoms. This concept is crucial for understanding how atoms interact and bond with each other, influencing the physical properties of substances, including their state at various temperatures.

Phase Changes and Solid Structure

Phase changes refer to the transitions between solid, liquid, and gas states of matter, which occur due to changes in temperature and pressure. The solid structure of argon at low temperatures, such as below 83 K, involves close-packed arrangements of atoms, which affects its physical properties. Understanding these concepts helps in comparing the solid state of argon with its atomic radius and other characteristics.