Electric Circuits and Energy Transfer

Electric Circuits

• A circuit is a path through which electric current flows
• Components:
  • Source (e.g. battery)
  • Conductors (e.g. wires)
  • Resistance (e.g. light bulb)
  • Load (e.g. device using electricity)
• Types of circuits:
  • Series circuit: components connected one after the other
  • Parallel circuit: components connected between the same two points

Energy Transfer

• Energy can be transferred from one object to another through different methods:
  • Conduction: direct contact between objects
  • Convection: movement of fluids
  • Radiation: electromagnetic waves
• Energy can be transformed from one form to another:
  • Kinetic energy: energy of motion
  • Potential energy: stored energy
  • Thermal energy: energy of heat
  • Electrical energy: energy of moving charged particles

Cell Structure

• Cell membrane: outer layer of the cell, semi-permeable and regulates what enters and leaves the cell
• Cytoplasm: jelly-like substance inside the cell membrane, where metabolic processes occur
• Nucleus: contains genetic material (DNA)
• Mitochondria: site of cellular respiration, where energy is produced
• Ribosomes: site of protein synthesis

Ecosystems

• An ecosystem is a community of living and non-living things interacting with each other:
  • Biotic factors: living components (e.g. plants, animals)
  • Abiotic factors: non-living components (e.g. water, sunlight, temperature)
• Energy flows through ecosystems:
  • Producers (e.g. plants) convert sunlight into energy
  • Consumers (e.g. animals) obtain energy by consuming producers or other consumers
  • Decomposers (e.g. bacteria) break down dead organisms, releasing nutrients back into the ecosystem

Sound Waves

• Sound waves are a type of mechanical wave that transfer energy through a medium (e.g. air, water, solid objects)
• Characteristics:
  • Frequency: number of oscillations per second
  • Amplitude: maximum displacement of the wave from its equilibrium position
  • Wavelength: distance between two consecutive points on the wave that are in phase
• Sound waves can be reflected, refracted, and absorbed

Separation Techniques

• Methods used to separate mixtures or components:
  • Filtration: separating particles based on size
  • Centrifugation: separating particles based on density
  • Chromatography: separating particles based on their interactions with a stationary phase
  • Distillation: separating particles based on their boiling points

Particle Properties

• Properties of particles:
  • Charge: positive or negative
  • Mass: amount of matter in a particle
  • Size: diameter of the particle
  • Shape: geometric shape of the particle
• Types of particles:
  • Atoms: smallest unit of a chemical element
  • Molecules: group of atoms bonded together
  • Ions: atoms or groups of atoms with a net charge

Atomic Structure

• Atomic structure:
  • Nucleus: protons and neutrons
  • Electron cloud: electrons orbiting the nucleus
• Subatomic particles:
  • Protons: positively charged, found in the nucleus
  • Neutrons: no charge, found in the nucleus
  • Electrons: negatively charged, orbiting the nucleus
• Electron arrangement:
  • Energy levels: electrons occupy specific energy levels around the nucleus
  • Valence electrons: outermost energy level, involved in chemical bonding

Electric Circuits

• A circuit is a path through which electric current flows
• Components of a circuit: source (e.g. battery), conductors (e.g. wires), resistance (e.g. light bulb), and load (e.g. device using electricity)
• Types of circuits: series circuit (components connected one after the other) and parallel circuit (components connected between the same two points)

Energy Transfer

• Energy can be transferred from one object to another through conduction (direct contact), convection (movement of fluids), and radiation (electromagnetic waves)
• Energy can be transformed from one form to another, including kinetic energy (energy of motion), potential energy (stored energy), thermal energy (energy of heat), and electrical energy (energy of moving charged particles)

Cell Structure

• Cell membrane: semi-permeable outer layer of the cell that regulates what enters and leaves the cell
• Cytoplasm: jelly-like substance inside the cell membrane where metabolic processes occur
• Nucleus: contains genetic material (DNA)
• Mitochondria: site of cellular respiration, where energy is produced
• Ribosomes: site of protein synthesis

Ecosystems

• An ecosystem is a community of living and non-living things interacting with each other
• Biotic factors: living components (e.g. plants, animals)
• Abiotic factors: non-living components (e.g. water, sunlight, temperature)
• Energy flows through ecosystems: producers convert sunlight into energy, consumers obtain energy by consuming producers or other consumers, and decomposers break down dead organisms, releasing nutrients back into the ecosystem

Sound Waves

• Sound waves are a type of mechanical wave that transfer energy through a medium (e.g. air, water, solid objects)
• Characteristics of sound waves: frequency (number of oscillations per second), amplitude (maximum displacement of the wave from its equilibrium position), and wavelength (distance between two consecutive points on the wave that are in phase)
• Sound waves can be reflected, refracted, and absorbed

Separation Techniques

• Methods used to separate mixtures or components: filtration (separating particles based on size), centrifugation (separating particles based on density), chromatography (separating particles based on their interactions with a stationary phase), and distillation (separating particles based on their boiling points)

Particle Properties

• Properties of particles: charge (positive or negative), mass (amount of matter in a particle), size (diameter of the particle), and shape (geometric shape of the particle)
• Types of particles: atoms (smallest unit of a chemical element), molecules (group of atoms bonded together), and ions (atoms or groups of atoms with a net charge)

Atomic Structure

• Atomic structure consists of a nucleus (protons and neutrons) and an electron cloud (electrons orbiting the nucleus)
• Subatomic particles: protons (positively charged, found in the nucleus), neutrons (no charge, found in the nucleus), and electrons (negatively charged, orbiting the nucleus)
• Electron arrangement: energy levels (electrons occupy specific energy levels around the nucleus) and valence electrons (outermost energy level, involved in chemical bonding)