STATES OF MATTER

 Al D. Deacon 

Founder: Gold'N Geniuz 

Physicist and Educator 

1. Explain how evidence supports the particulate theory of matter

• The particulate theory states that all matter is made up of tiny particles (atoms, molecules, or ions) that are in constant motion.
• Evidence:
  • Diffusion: The spreading of a gas (e.g., perfume in a room) or a solute in a liquid (e.g., potassium permanganate in water) shows that matter consists of moving particles.
  • Brownian motion: The random movement of microscopic particles in a fluid (observed under a microscope) supports the idea that smaller, invisible particles (such as air or water molecules) are constantly in motion.
  • Expansion and compression of gases: Gases can be compressed and expanded, indicating that particles have space between them.

2. Distinguish among the three states of matter

Property	Solid	Liquid	Gas
Shape	Fixed	Takes the shape of the container	No fixed shape
Volume	Fixed	Fixed	Changes (fills container)
Particle arrangement	Closely packed in a fixed pattern	Loosely arranged, able to flow	Very far apart, move freely
Particle movement	Vibrates in place	Moves and slides past each other	Moves randomly and rapidly

3. Explain the changes between the three states of matter in terms of energy and particle arrangement

• Melting (solid → liquid): Heat energy is absorbed, increasing particle movement until they overcome their fixed positions.
• Evaporation/Boiling (liquid → gas): More heat energy is absorbed, allowing particles to move freely and escape as gas.
• Condensation (gas → liquid): Gas loses energy, causing particles to slow down and come closer together to form a liquid.
• Freezing (liquid → solid): Particles lose energy, slowing down and arranging into a fixed structure.
• Sublimation (solid → gas) & Deposition (gas → solid): Direct transitions due to significant energy changes (e.g., dry ice subliming into carbon dioxide gas).