Question

Is the density of a gaseous substance likely to be larger or smaller than the density of a liquid or solid substance at the same temperature? Why?

Short answer

In conclusion, the density of a gaseous substance is likely to be smaller than the density of a liquid or solid substance at the same temperature due to the difference in particle arrangement and motion in each state of matter. Gas particles are farther apart and occupy more space, resulting in a lower density compared to the closely-packed particles in liquids and solids.

Step-by-step solution

Understand the states of matter.

In general, there are three states of matter: solid, liquid, and gas. The primary difference between these states lies in the arrangement and motion of their particles. In solids, particles are tightly packed together and have little molecular movement. In liquids, particles are slightly farther apart and have more movement. In gases, particles are much farther apart and have the most movement among the three states.

Consider the property of density.

Density is defined as the mass of a substance divided by its volume (Density = mass/volume). In other words, it is a measure of how much matter is within a given space. Thus, when particles are closer together, the density is higher, and when particles are farther apart, the density is lower.

Compare the densities of gases versus liquids and solids.

Due to the molecular arrangement and motion of particles, gases have a much lower density compared to liquids and solids at the same temperature. This is because gas particles are farther apart and occupy a much larger volume for a given amount of mass. On the other hand, liquids and solids have higher densities due to their particles being more tightly packed.

Conclusion.

In conclusion, the density of a gaseous substance is likely to be smaller than the density of a liquid or solid substance at the same temperature. This is primarily due to the difference in particle arrangement and motion in each state of matter, causing gas particles to occupy more space and thereby have a lower density compared to their liquid and solid counterparts.

Key concepts

Density of Gases

When we talk about density, we refer to how tightly matter is packed within a certain volume. For gases, the density tends to be much lower than that of liquids or solids. This is because the molecules in a gas are spread out widely, giving gases their lightweight and ethereal properties. Compared to liquids and solids, the molecules in a gas move more freely and rapidly, occupying a greater volume for the same amount of mass.

Imagine you have a balloon filled with air. The gas molecules inside the balloon are constantly moving and bouncing off of one another, but there's a lot of space between them. If you compared this to the same volume of water or a solid block, you would find that there are many more water or solid molecules in that space. Consequently, gas has a lower density, expressed mathematically as the ratio of mass to volume, or \(density = \frac{mass}{volume}\).

Molecular Arrangement

The distinct characteristics of solids, liquids, and gases arise because of their molecular arrangement. In solids, molecules are packed closely together in a specific, rigid structure, which allows them to vibrate in place, but not move around freely. This arrangement results in solids having a definite shape and volume.

Liquids, on the other hand, have molecules that are less tightly bound to each other. They're able to move past one another, which grants them the ability to flow and assume the shape of their container, while still maintaining a relatively consistent volume.

Gases have the most relaxed arrangement; their molecules are so far apart and move so quickly that they completely fill any container they're in, no matter the shape. This capacity to expand and the lack of fixed volume or shape is what separates gases distinctly from solids and liquids.

Solid Liquid Gas Differences

Understanding the differences between solids, liquids, and gases is crucial in grasping the concept of states of matter. These differences manifest in their density, but also in their structure and behavior.

Structure and Volume

Solids have a fixed structure and retain their shape and volume regardless of the container. Liquids have a definite volume but no fixed shape, adapting to the shape of their container. Gases lack both a fixed shape and volume, spreading out to fill the entire available space.

Compressibility

Solids are very hard to compress because their particles are already tightly packed. Liquids are slightly compressible for the same reason. Gases are easily compressed since their particles are far apart and have room to be brought closer together.

Expansion and Flow

Solids expand very little with heat as the particles are tightly bound. Liquids expand more than solids but less than gases, and they flow easily, taking the shape of the container. Gases expand significantly when heated and flow freely, filling any space they're in.

This comparison shows how temperature and pressure affect each state differently, and how their molecular arrangement dictates their physical properties.