Question

How do gases compare with liquids and solids in terms of the distance between their molecules?

Short answer

In gases, the distance between molecules is much larger than in solids and liquids.

Step-by-step solution

- Understand the States of Matter

There are three primary states of matter: solids, liquids, and gases. Each state is characterized by the arrangement and movement of its molecules.

- Distance Between Molecules in Solids

In solids, molecules are closely packed in a fixed, orderly arrangement. The distance between molecules is minimal, resulting in a rigid structure.

- Distance Between Molecules in Liquids

In liquids, molecules are still close to one another but are not in a fixed position. They are arranged more loosely than in solids, allowing them to move past one another. The distance between molecules is slightly greater than in solids.

- Distance Between Molecules in Gases

In gases, molecules are much further apart compared to solids and liquids. They move freely and spread out to fill the available space. The distance between molecules in gases is much larger, making gases less dense.

- Compare the Distances

To summarize, the distance between molecules increases from solids to liquids to gases. In gases, the distance between molecules is the greatest, allowing them to expand and occupy more space.

Key concepts

Solids

Solids are one of the three primary states of matter. A key characteristic of solids is their rigid structure. The molecules in solids are tightly packed in a fixed, orderly arrangement.
Due to this close packing, the molecular distance in solids is minimal. This arrangement gives solids a definite shape and volume.
For example, think of a rock or a block of ice. They keep their shape because the molecules can't move past one another easily.

Liquids

Liquids are another primary state of matter. Unlike solids, molecules in liquids are not in a fixed position.
The molecules are more loosely arranged, allowing them to move around and slide past one another. This gives liquids the ability to flow and take the shape of their container.
The distance between molecules in liquids is slightly larger than in solids, but they are still relatively close.

• Think of water. It takes the shape of any container you pour it into, yet it maintains a constant volume.
• Liquids have a definite volume but no fixed shape.

Gases

Gases are the third primary state of matter. In gases, molecules are much further apart compared to solids and liquids.
The molecules move freely in all directions and spread out to fill the available space. This means gases have no fixed shape and no definite volume.
The vast distance between molecules in gases makes them much less dense than solids or liquids.

• Think of the air around us. It expands to fill any room or container, and you can compress it easily.

Molecular Distance

Molecular distance refers to the space between individual molecules within a substance.
In solids, this distance is tiny because of the tight packing of molecules. In liquids, the molecular distance increases slightly due to the looser arrangement of molecules.
In gases, molecules are very far apart, resulting in the largest molecular distances. These differences in molecular distance explain why solids are rigid, liquids can flow, and gases can expand to fill a space.

Density

Density is a measure of how much mass is contained in a given volume.
The formula to calculate density is: \rho = \frac{m}{V}, where \( \rho \) is the density, \(m\) is the mass, and \(V\) is the volume.
In solids, because the molecules are tightly packed, the density is usually high. In liquids, the moderate molecular distance results in a medium density.
Gases, with their molecules far apart, have the lowest density of the three states of matter. Understanding density helps explain why objects like ice (a solid) float on water (a liquid) and why hot air balloons rise.