Core Concepts
In this tutorial, you will learn about the properties of the solid, liquid, and gas phases of matter. Solids, liquids and gases are all around us, they are the three main states of matter – but how many of their properties do you really know? Let’s find out!
Topics Covered in Other Articles
Vocabulary
Amorphous – without form
Capillary action – attraction of the surface of a liquid to the surface of a soli
Crystalline – the particles of the solid are arranged in an orderly, geometric, repeating pattern
Diffusion – spontaneous mixing of the particles of two substances caused by their motion
Intermolecular forces – forces of attraction or repulsion existing between neighboring particles.
Surface tension – force that pulls adjacent parts of a liquid’s surface together, decreasing the surface area to the smallest size possible
Viscosity – resistance to motion that exists between the molecules of a liquid when they move past each other
Properties of Solids
In the solid state, the particles do not have enough energy to overcome the strong intermolecular forces, which means they are tightly held against each other. As a result, solids have a definite shape and volume. They don’t pour like a liquid.
The particles vibrate back and forth within their fixed positions and do not move freely. Solids are incompressible and have high density, compared to liquids and gases. They can be crystalline, like table salt, or amorphous, like glass, rubber or plastic.
Many elements exist as solid-state at room temperatures, such as sodium, vanadium and magnesium.
Properties of Liquids
In the liquid state, the intermolecular forces between the particles are strong enough to have a definite volume. However, they are not strong enough to have a definite shape. Consequently, the particles move freely, but they are still attracted to each other. Liquids are incompressible but conform to the shape of the container. They are slightly less dense than the solid state, 10% less dense on average. They usually exhibit surface tension, capillary action, and viscosity.
Mercury is an example of a liquid metal with a very high cohesion and surface tension, which makes it easily bead up when spilled.
Water is a liquid with many unusual properties, such as expanding when it freezes. This is due to its hydrogen bonding.
There are many misconceptions of iodine not existing in a liquid state. However, you can find out why so many are quick to believe this false idea here.
Properties of Gases
In the gaseous state, the particles have enough kinetic energy to overcome the weak intermolecular forces between each other. Therefore, they move in random motion without being attracted to each other. As a result, gases have neither a definite shape nor volume. They consist of widely separated molecules.
Gases are compressible and have low density – often 1,000 times less dense than the liquid or solid phase. Gases can diffuse, and they exert pressure on surfaces with which they collide..
At room temperature, some elements exist as gas. Examples of these elements is fluorine, hydrogen and helium.
Examples
Examples of Solids
Ice, glass, rock, salt, sugar, concrete, gold, wood, concrete
Examples of Liquids
Water, juice, coffee, mercury, bromine
Examples of Gases
Carbon dioxide, oxygen, hydrogen, helium, uranium hexafluoride, air
Summary of Properties
