Solids, liquids, and gases are three states of matter, and they behave very differently from one another. Let's break it down in simple terms.

Solids hold their shape because of how their tiny particles are packed together. According to a theory called the Kinetic Molecular Theory (KMT), the particles in solids are tightly packed in a fixed and neat arrangement.

• This close packing lets the particles vibrate a little but not move around freely.
• Because of this, solids keep a definite shape and don't easily change when something pushes on them.
• The strong forces between the particles keep them together, making it hard for outside forces to change their shape.

Liquids are a bit different. The particles in liquids are still close together, but they’re not stuck in one spot.

• The forces holding the particles together are weaker than in solids.
• This allows the particles to slide past each other, which is why liquids can flow.
• When you pour a liquid into a cup, it takes the shape of the cup but still has a set volume—it won’t just disappear or expand like a gas.

Gases have even more freedom. The particles in a gas are far apart and zooming around.

• They have enough energy to break free from the forces that hold particles in solids and liquids together.
• Because of this, gases will fill up any container they are in, which means they don’t have a fixed shape or volume.

In summary, how particles are arranged and how much energy they have makes solids, liquids, and gases behave differently. These differences help us understand their physical properties and how they react to outside forces.