Essential Science Concepts: Matter, Cells, Light, and Systems

Unit A: Mix & Flow of Matter

States of Matter

• Solid: Definite shape and volume
• Liquid: Indefinite shape, definite volume
• Gas: Indefinite shape and volume

Particle Model

Tiny particles with space, motion, attraction, and speed that increases with heat.

Mixtures

• Pure: 1 type (e.g., water)
• Mixture: 2+ substances
• Homogeneous: Uniform composition
• Heterogeneous: Visible parts

Solubility Terms

Solute + Solvent = Solution

• Saturated: No more dissolves
• Supersaturated: Extra dissolved

Viscosity

Resistance to flow. Increased temperature = decreased viscosity (in liquids).

Density

D = m / V. Generally: Solids > Liquids > Gases.

Buoyancy

• Float: If average density is less than the fluid.
• Archimedes’ Principle: Buoyant force = weight of fluid displaced.

Pressure

P = F / A (measured in Pascals).

Fluid Systems

• Hydraulic: Uses liquid
• Pneumatic: Uses gas

Unit B: Cells & Systems

Living Things

Characteristics: Cells, energy, growth, response, and reproduction.

Levels of Organization

Organism → System → Organ → Tissue → Cell

Cell Parts

• Nucleus: Control center
• Membrane: Entry/exit control
• Cytoplasm: Holds parts
• Wall/Chloroplast: Plants only
• Mitochondria: Energy production
• Vacuole: Storage

Transport

• Diffusion: High to low concentration
• Osmosis: Diffusion of water

Body Systems

• Respiratory: Lungs for gas exchange
• Circulatory: Heart for transport
• Digestive: Stomach/intestine for nutrients
• Excretory: Kidneys for waste

Unit C: Light & Optics

Reflection Law

Angle of incidence = Angle of reflection.

Mirrors

• Concave: Focuses light
• Convex: Spreads light

Wave Parts

Crest, trough, and wavelength.

EM Spectrum (Low to High Energy)

Radio → Micro → IR → Visible → UV → X-ray → Gamma

Light Colors

• Primary: Red, Green, Blue
• Mix: Red + Green = Yellow

Eye Parts

Cornea, lens, retina, iris, and pupil.

Unit D: Mechanical Systems

Simple Machines

Lever, wedge, pulley, screw, wheel & axle, and inclined plane.

Lever Classes

• 1st: Fulcrum in center
• 2nd: Load in center
• 3rd: Effort in center

Formulas

• MA: Load / Effort
• SR: Input distance / Output distance
• Work: F × d (Joules)
• Efficiency: (Output / Input) × 100%

Unit E: Water Systems

Earth's Water

97% salt water, 3% fresh water.

Watershed

Area draining into a body of water.

Water Quality Factors

pH, temperature, dissolved oxygen (DO), turbidity, and pollution.

Purification

Filtration, distillation, and chlorination.

Power of Water

Erosion, waves, tides, and glaciers.

Climate Effects

Oceans regulate temperature and moisture.