The Particulate Nature of Matter
What is it?
The particulate nature of matter is the idea that all matter is made of tiny particles.
- These particles are called molecules.
- Molecules are made of even smaller particles called atoms.
What is an Atom?
An atom is the smallest particle of matter. It cannot be seen with the eyes and cannot be broken down further in a chemical reaction.
Evidence of Particles in Matter
We can prove that matter is made of particles by using diffusion.
What is Diffusion?
Diffusion is the movement of particles from a place of high concentration to a place of low concentration.
- It happens in liquids and gases.
- It happens faster in gases because gas particles move faster and are far apart.
- Diffusion does not happen in solids because the particles are tightly packed and cannot move freely.
Experiment: Diffusion in Liquids
Materials Needed:
- Beaker
- Water
- Potassium permanganate crystals (purple)
- Thistle funnel
Steps:
- Put the thistle funnel into the beaker.
- Drop a few potassium permanganate crystals into the beaker through the funnel.
- Carefully pour water into the beaker (funnel still inside).
- Remove the funnel and leave the beaker still for 5 minutes.
Observation:
- The purple colour spreads throughout the water.
Explanation:
- The potassium permanganate particles move and mix with the water particles.
- This shows that particles are always moving—a proof that matter is made of tiny moving particles.
Examples of Diffusion in Everyday Life
- Smelling food when you enter a restaurant
- Sugar spreading when it dissolves in water
- Coffee granules mixing in hot water
- Smelling perfume from someone nearby