States of Matter: Evaporation, Freezing, Condensation

Evaporation

• Evaporation is a vaporization process occurring only at a liquid's surface.
• Particles overcome attractive forces and air pressure to evaporate.
• The process requires the particles to gain enough energy to overcome forces.

Freezing

• Freezing is the change of state from liquid to solid.
• It requires the removal of thermal energy.
• As thermal energy is removed, particles slow down and have less energy to overcome attractive forces.
• This leads to the formation of an organized structure (solid).

Condensation

• Condensation is the change of state from gas to liquid.
• It involves the removal of thermal energy from a gas.
• Slower-moving particles in the gas cannot overcome attractive forces with surrounding particles.
• This causes them to clump together forming a liquid.

Chemical Change

• A chemical change is a change in matter where the substance transforms into new substances with different physical properties.
• Indicators of a chemical change include color change and odor change.

Population Size

• Population size can increase but also decrease.
• Example: Field mice population decreases in winter due to less food.
• Natural disasters (floods, fires, volcanic eruptions) impact population size.
• Certain population sizes can decrease to a point threatening the entirety of the species.

Changes of State

• From gas to liquid: condensation
• From solid to gas: sublimation
• The number of particles remains the same during a change of state.
• The mass of the matter is unchanged during a change of state.

Physical Change

• A physical change alters one or more physical properties of a substance.
• The substance's identity stays the same.

Examples of Physical Change

• Breaking glass
• Mixing candies
• Shredding paper
• Folding paper
• Melting ice

Involved in Changing State

• Transferring energy to/from a substance changes the state.
• A form of this energy is thermal energy/heat.

Changing State of Matter

• Melting: solid to liquid
• Evaporation: liquid to gas
• Freezing: liquid to solid

Mixtures

• A mixture is matter that varies in composition.
• Types of mixtures:
  • Heterogeneous: substances are not evenly mixed (e.g., fruit salad).
  • Homogeneous: substances are evenly mixed (e.g., tea with sugar).
• Methods for separating mixtures:
  • Mechanical separation
  • Filtration
  • Evaporation
  • Magnetism
  • Separation funnel
  • Distillation

Ecology - Symbiosis

• Symbiosis: a close long-term relationship between two species.
• Types of symbiotic relationships:
  • Commensalism: one species benefits, the other is unaffected.
  • Parasitism: one species benefits, the other is harmed.
  • Mutualism: both species benefit.

Ecology - Limiting Factors

• Limiting factors restrict population size.
• Examples of limiting factors:
  • Water
  • Food
  • Sunlight
  • Temperature
  • Space/shelter

Ecology - Biotic Potential

• Biotic potential: the potential growth of a population under ideal conditions (no limiting factors).

Ecology - Carrying Capacity

• Carrying capacity is the largest number of individuals of a species an environment can support.

Overpopulation

• Overpopulation occurs when a population size becomes so large it damages the environment.