States of Matter: Solid, Liquid, and Gas

• Matter exists as solid, liquid, gas, and plasma.
• A substance's state is determined by the behavior and arrangement of its particles (atoms, molecules, or ions) and the energy they possess.
• State transitions are physical changes involving energy and arrangement alterations, not chemical changes, which would alter the substance's composition.

Solid State

• Solids maintain a definite shape and volume.
• Solids' particles are tightly packed, with strong intermolecular forces keeping them fixed.
• Solids are generally incompressible because their particles are closely packed.
• Crystalline solids feature a highly ordered, repeating particle arrangement, while amorphous solids lack long-range order.
• Crystalline solids melt at a specific temperature, whereas amorphous solids soften over a temperature range.
• Examples include ice, rock, wood, and metal.

Liquid State

• Liquids have a definite volume but assume the shape of their container.
• Liquid particles are close but can move past each other, enabling flow.
• Intermolecular forces in liquids are weaker than in solids but stronger than in gases.
• Liquids are nearly incompressible.
• Surface tension and viscosity arise from intermolecular forces in liquids.
• Examples include water, oil, and blood.

Gaseous State

• Gases lack a definite shape or volume, expanding to fill any container.
• Gas particles are widely spaced and move randomly.
• Intermolecular forces in gases are very weak.
• Gases are highly compressible.
• Gases follow the ideal gas law, which relates pressure, volume, temperature, and the number of moles of gas.
• Examples include air, oxygen, and helium.

Plasma State

• Plasma is an ionized gas carrying an electrical charge.
• Plasmas are usually very hot, consisting of ions, electrons, and neutral particles.
• Plasma is the most abundant state of matter in the universe, found in stars, lightning, and the ionosphere.
• Plasmas are electrically conductive and respond to magnetic fields.
• Lightning, the sun, and neon signs exemplify plasmas.

Phase Transitions

• Phase transitions are physical processes where a substance changes from one state of matter to another.

Melting

• This is the transition from solid to liquid.
• Melting happens when a solid's temperature reaches its melting point.
• Energy (heat) input is needed to overcome the intermolecular forces holding the solid together.

Freezing

• This is the transition from liquid to solid.
• Freezing occurs when a liquid's temperature drops to its freezing point.
• Energy (heat) is released as intermolecular forces strengthen and particles arrange into a fixed structure.

Vaporization

• This is the transition from liquid to gas.
• Vaporization occurs through evaporation (at the surface) or boiling (throughout the liquid).
• Energy input overcomes intermolecular forces, allowing particles to enter the gaseous phase.

Condensation

• This is the transition from gas to liquid.
• Condensation happens as a gas cools to its condensation point.
• Energy is released when intermolecular forces strengthen, and particles draw closer to form a liquid.

Sublimation

• This is the transition from solid to gas, skipping the liquid phase.
• Energy input overcomes intermolecular forces, allowing particles to directly enter the gaseous phase.
• Dry ice (solid carbon dioxide) sublimating at room temperature is an example.

Deposition

• This is the transition from gas to solid, skipping the liquid phase.
• Energy is released as particles combine and form a solid structure directly from the gaseous phase.
• Frost forming on a cold surface is an example.

Ionization

• This is the transition from gas to plasma.
• Ionization happens when a gas is heated to high temperatures or exposed to strong electromagnetic fields.
• Atoms lose electrons, forming a mix of ions and free electrons.

Recombination

• Transition from plasma to gas.
• Occurs when the temperature of a plasma cools, allowing ions to capture free electrons and revert back to a neutral gas state.