12 / 06 Monday Kaupapa: Explain why metal objects expand when heated, using Particle Theory

Do you remember? What is particle theory? Define “particles” Why does the balloon expand?

Particle Theory Everything is made up of tiny particles. Particles are defined as “the smallest bits” of a substance. The particles are active (they are constantly moving).

Particle Theory (contd.) When the particles absorb heat (when they are heated), they become more active.

More Evidence: Air Expansion

More Evidence: Collapsing Cans

Practical – Metal Expansion

Why does the metal ball expand when heated?

Metal Expansion When the metal ball is heated, it expands – WHY? Because the particles become more active, which means they are pushing each other out so they become more spread out,– causing the ball to expand.

“Particle Theory” Are you convinced?

Real life examples:

Real life examples:

Real life examples:

Real life examples:

Real life examples:

Real life examples:

Real life examples:

Real life examples:

Extension: What happens if you leave a glass of water in a freezer?

What have we learnt today? What is particle theory? Why does the metal ball expand when heated?