Characteristics of Solids

Solids have special features that make them different from liquids and gases. Let's look at some key points about solids:

1. Shape and Volume

   • Fixed Shape: Solids keep their shape because their tiny particles are packed close together. For example, a cube of ice keeps its shape until it melts.
   • Fixed Volume: Solids have a steady volume, which means the space they take up doesn’t change. For example, a 100g block of wood will always take up the same space, no matter where it is.

2. Particle Arrangement

   • Tightly Packed: The particles in solids are packed tightly in a regular pattern. This makes it hard to squish them. On the other hand, particles in liquids and gases are more spread out.
   • Vibrating Movement: Particles in solids can only shake in place. In liquids, they can slide past each other, and in gases, they move around quickly.

3. Density

   • Higher Density: Usually, solids are denser than liquids, and liquids are denser than gases. For instance, iron is much denser than water. Iron has a density of about 7.87 grams per cubic centimeter, while water's density is around 1 gram per cubic centimeter.

4. Melting Point

   • Set Melting Points: Each solid has a specific melting point—the temperature at which it turns into a liquid. For instance, ice melts at 0 degrees Celsius.

5. Immutability Under Pressure

   • Not Easily Compressed: Solids don’t get much smaller when you push on them. In contrast, both liquids and gases can change their volume more noticeably when pressure is applied.

In short, solids are known for their fixed shape and volume, tightly packed particles, higher density, specific melting points, and the fact that they don’t change much when pressure is applied. These features clearly set them apart from liquids and gases.