Term 2: Classification of Matters

Term Two:

(3) Classification of Matter


In this topic, the 3 different states of matter was reiterated again. Although we learnt this in P5, the things we learnt this year was much more in depth and there were more knowledge to be learnt for the topic. Besides the basic knowledge like knowing that gas has no fixed shape and volume, we were also introduced to the Kinetic Particle Theory and other theories which told us the explanations behind these basic facts that we already knew. 

I am very interested in Brownian motion theory as it turned out to be much more than expected and that amazed me and intrigued me. I feel that matter is very broad and there are many things to learn. I really hope it is fun.

  However, I know that much excitement awaits me soon. 

Kinetic Particle Theory

Brownian motion

Particles in a liquid

They are randomly arranged with the particles sightly further away from each other as strong attractive forces. This explains why they have a definite shape and volume, as compared to solids, resulting in them having relatively high densities. These particles slide past one another, and are free to move about but confined in the vessel containing it. They have relatively strong attractive forces, explaining why they have a fixed volume but will take the shape of its container.

Particles in a gas

They are very far apart, and are randomly arranged and will occupy any available space, thus giving them low densities. They have relatively little attraction between them, thus explaining why gases have no fixed volume and shape, and can be compressed.

What happens to the solid particles when it is heated till it melts?

When a solid is heated, the particles absorb heat energy. The particles gain kinetic energy and start to vibrate faster and moving apart. At a certain temperature known as the melting point, the particles have enough kinetic energy to overcome the strong attractive forces holding them together as a solid. They start to break away from one another and the solid becomes a liquid. They then roll and side past one another once in a liquid state.