ο»Ώπ¦ Topic 1-10 (Biology all)
Topic 1: Life Processes β Structure and Function of Living Organisms
1. The Seven Life Processes
All living things do these seven things:
* Move β even plants can move, like turning toward the Sun.
* Respire β release energy from food.
* Sense β respond to changes around them.
* Grow β become bigger or develop.
* Reproduce β make new living things.
* Excrete β get rid of waste.
* Take in nutrition β get food or nutrients.
2. Life Processes in the Real World
* These seven life processes can be seen in many different living things around us and in other environments.
3. Breathing vs Respiration
* Breathing is taking air in and out of the lungs.
* Respiration is a chemical reaction in cells to make energy.
4. Respiration in Cells
* Both plant and animal cells respire to release energy.
* The energy is stored in an ATP molecule (you donβt need to know details about ATP).
5. Types of Respiration
* Aerobic respiration uses oxygen:
* Word equation:
Glucose + Oxygen β Carbon dioxide + Water + Energy
* Symbol equation:
CβHββOβ + 6Oβ β 6COβ + 6HβO + energy
* Anaerobic respiration happens without oxygen
* Word equation:
Glucose -> Lactic Acid
* Symbol equation:
C6H12O6->2C3H6O3
6. Viruses
* Viruses are tiny particles with a simple structure.
* They reproduce by infecting living cells (they cannot reproduce by themselves).
* Viruses are called obligate parasites because they need a host cell to live and multiply.
* Viruses are not classed as living things because they do not carry out all seven life processes on their own.
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Topic 2: Cells and Organisation β Structure and Function of Living Organisms
1. Structure of Animal Cells
* A typical animal cell has:
* Cell membrane β surrounds and protects the cell
* Cytoplasm β jelly-like substance where reactions happen
* Mitochondria β release energy through respiration
* Nucleus β controls the cell and contains DNA
2. Plant and Animal Cells: Similarities and Differences
* Both plant and animal cells have:
* Cell membrane, cytoplasm, mitochondria, and nucleus
* Only plant cells also have:
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* Cell wall β provides support
* Chloroplasts β carry out photosynthesis
* Permanent vacuole β stores water and keeps the cell firm
3. Identifying Cell Parts
* You should be able to spot and label these in animal and plant cells:
* Cell wall
* Cell membrane
* Cytoplasm
* Nucleus
* Permanent vacuole
* Mitochondria
* Chloroplasts
4. Functions of Cell Parts
* Cell wall β supports and protects plant cells
* Cell membrane β controls what goes in and out of the cell
* Cytoplasm β where most cell activities happen
* Nucleus β contains genetic material and controls the cell
* Vacuole β stores cell sap and keeps the cell firm
* Mitochondria β release energy from food (respiration)
* Chloroplasts β absorb sunlight for photosynthesis
5. Levels of Organisation in Living Things
Multicellular organisms are organised in levels:
* Cells β Tissues β Organs β Organ systems β Organism
6. Main Human Organs and Organ Systems
Know the function of these major parts:
* Lungs β for breathing and gas exchange
* Kidneys β filter waste from blood
* Skin β protects and helps control body temperature
* Brain β controls the body
* Heart β pumps blood
* Liver β processes nutrients and removes toxins
* Stomach, small and large intestines β digest food and absorb nutrients
* Nervous system β sends signals around the body
* Skeleton and muscles β support movement and protect organs
7. Plant, Animal and Bacterial Cells
* Similarities: All have a cell membrane and cytoplasm
* Differences:
* Bacteria have no nucleus and no mitochondria
* Bacteria are much smaller than plant or animal cells
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Topic 3: Pathogens β Structure and Function of Living Organisms
1. Pathogens and parasites
* A pathogen is a microorganism that causes disease, such as viruses, bacteria, fungi, and protoctists.
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* A parasite lives on or inside another living thing and takes nutrients from it, often causing harm.
2. Types of pathogens
Diseases can be caused by:
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* Viruses, such as flu
* Smaller than bacteria
* Have no cell wall, no mitochondria, and no nucleus
* Cannot live on their own and reproduce only inside living cells
* Bacteria, such as those that cause cholera and Salmonella
* Single-celled organisms
* Have a cell wall, cell membrane, and cytoplasm
* Do not have a nucleus
* Fungi, such as the one that causes athleteβs foot
* Some are single-celled (like yeast), others are multicellular (like mushrooms)
* Have a cell wall, cell membrane, cytoplasm, mitochondria, and a nucleus
* Protoctists, such as the one that causes malaria
* Usually single-celled and have various structures
3. Antibiotics and viruses
* Antibiotics are used to treat bacterial infections.
* They do not work against viruses because viruses do not have the structures that antibiotics target.
4. Problems with antibiotic overuse
* Using antibiotics too often in people or animals can lead to antibiotic resistance.
* Resistant bacteria are harder to kill, and infections become more difficult to treat.
5. Vaccination
* Vaccines help prevent disease by training the immune system to fight specific pathogens.
* Vaccination can stop diseases from spreading in a community, which also protects people who are not vaccinated.
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Topic 4: Movement of Molecules
1. Diffusion
* Diffusion is how substances move from a high concentration to a low concentration.
* It helps substances like oxygen and carbon dioxide move in and out of cells.
2. Diffusion Gradient
* A diffusion gradient is the difference in concentration between two areas.
* The bigger the difference, the faster diffusion happens.
3. Factors Affecting Diffusion
* Higher temperature makes particles move faster, so diffusion happens quicker.
* A bigger difference in concentration also speeds up diffusion.
4. Surface Area to Volume Ratio
* Cells with a larger surface area compared to their volume can absorb and release substances faster.
* You should know how to calculate and compare these ratios.
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Topic 5: The Digestive System
1. Digestive System Parts and Functions
* Includes teeth, salivary glands, oesophagus, stomach, pancreas, small and large intestines.
* These parts work together to break down food and absorb nutrients.
2. Balanced Diet
* A healthy diet contains carbohydrates, proteins, fats, vitamins, minerals, fibre, and water.
3. Starvation and Malnutrition
* Starvation means not eating enough food.
* Malnutrition means not getting enough of certain nutrients.
* Examples of nutrient deficiency diseases:
* Anaemia (iron)
* Blindness (vitamin A)
* Scurvy (vitamin C)
* Rickets (vitamin D)
4. Energy Needs
* People need different amounts of energy depending on their age and how active they are.
5. Energy in Foods
* Different foods provide different amounts of energy.
* For example, fats give more energy than carbohydrates or proteins.
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Topic 6: The Circulatory System
1. Single and Double Circulatory Systems
* Single circulatory systems (like in fish) have one loop.
* Double circulatory systems (like in humans) have two loops: one to the lungs and one to the rest of the body.
2. Main Parts and Their Functions
* Heart: pumps blood
* Arteries: carry blood away from the heart
* Veins: carry blood to the heart
* Capillaries: exchange substances with body cells
3. Pressure and Flow
* Arteries have high pressure and fast flow. Ty
* Veins have lower pressure and valves.
* Capillaries are very small and allow substance exchange.
4. Exercise and Heart Rate
* Exercise increases heart rate to pump more oxygen and nutrients to muscles.
* This helps the body work better during activity.
5. Measuring Pulse
* Pulse is measured in beats per minute by counting how many times your heart beats.
6. Graphs and Pulse Rate
* You should know how to read line graphs that show changes in pulse during and after exercise.
7. Lifestyle and Heart Health
* Smoking, unhealthy diet, lack of exercise, and stress can lead to heart disease.
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Topic 7: Plants β Structure, Photosynthesis, and Crop Yield
1. Functions of Roots, Stems, and Leaves
* Roots anchor the plant and absorb water and minerals (like nitrates for growth and magnesium for chlorophyll).
* Root hairs increase surface area for absorption.
* Stems support the plant and transport materials.
* Leaves carry out photosynthesis.
2. Plant Features in Different Habitats
* Plants adapt to their environments, for example:
* Desert plants have small, thick leaves.
* Arctic plants have low-growing structures.
* Temperate plants have broad, flat leaves.
3. Water and Mineral Transport
* Water and minerals are absorbed by roots and move up the stem in xylem vessels.
4. Fertilisers and Crop Yield
* Fertilisers help plants grow by providing nutrients.
* You should know how to set up and understand experiments testing fertiliser effects.
5. Leaf Adaptations for Photosynthesis
* Large surface area to absorb light
* Waxy surface to reduce water loss
* Stomata allow gases in and out
* Chloroplasts contain chlorophyll for photosynthesis
6. Photosynthesis Equations
* Word: carbon dioxide + water β glucose + oxygen
* Symbol: 6COβ + 6HβO β CβHββOβ + 6Oβ
7. Factors Affecting Photosynthesis
* Light intensity, carbon dioxide levels, and temperature affect the rate of photosynthesis.
* Be able to describe and interpret experiments on these factors.
8. Abiotic Factors and Crop Yield
* Crop yield is affected by non-living factors like sunlight, rainfall, temperature, and soil quality.
9. Selective Breeding in Plants
* Choosing the best plants to breed over generations can produce better crop varieties.
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Topic 8: Organisms and Their Environment β Interactions with the Environment
1. Adaptations to Habitats
* Organisms have features that help them survive in their environments.
* Example: polar bears have thick fur and fat; cacti store water and have spines.
2. Abiotic and Biotic Factors
* Abiotic = non-living (light, temperature, water)
* Biotic = living (predators, disease, competition)
3. Changing Environments and Organisms
* Changes in the environment (like pollution or climate change) can affect how many organisms live in a place and where they are found.
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Topic 9: Organisms and Their Environment β Interactions Between Living Organisms
1. Feeding Roles
* Producer: makes its own food (plants)
* Primary consumer: eats producers
* Secondary consumer: eats primary consumers
* Tertiary consumer: eats secondary consumers
* Decomposer: breaks down dead material
2. Feeding Relationships
* Food chains and food webs show how organisms depend on each other.
* Use terms like predator, prey, herbivore, carnivore, omnivore.
3. Pyramids of Number
* Show how many organisms are at each level in a food chain.
4. Energy Flow in Food Chains
* Food chains show how energy passes from one organism to another.
5. Energy Loss Between Levels
* Energy is lost as heat, movement, and waste β not all energy passes on to the next level.
6. Pyramids of Biomass
* Show the mass of living material at each stage of the food chain.
7. Key Terms
* Species: one type of organism
* Population: group of the same species
* Community: all living things in one area
* Habitat: where organisms live
* Ecosystem: community and its non-living environment
8. Competition
* Interspecific: between different species
* Intraspecific: within the same species
9. Interpreting Population Data
* Be able to read data and graphs showing population changes over time.
10. Why Populations Change
* Predator-prey relationships and environmental factors can cause numbers to rise and fall.
11. Predator-Prey Data
* Recognise patterns in population graphs (e.g. predator numbers rise after prey increases).
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Topic 10: Organisms and Their Environment β Further Interactions with the Environment
1. Role of Decomposers in Recycling Carbon
* Decomposers break down dead plants and animals.
* They release carbon back into the environment, which plants can use to grow.
* This process helps recycle carbon and maintain healthy ecosystems.
2. Human Activities that Produce Carbon Dioxide
* Burning fossil fuels in cars, factories, and power plants releases COβ.
* Deforestation reduces the number of trees that can absorb COβ.
* Agriculture, including livestock farming, releases COβ and other gases.
* Industrial processes like cement manufacturing produce COβ.
3. Impact of Carbon Dioxide on the Climate
* The enhanced greenhouse effect occurs when too much COβ traps more heat in the Earthβs atmosphere.
* Consequences of global warming include:
* Higher temperatures.
* Melting ice and rising sea levels.
* More extreme weather, like storms, floods, and droughts.
* Changes to ecosystems and wildlife.
Key Terms
* Carbon Cycle: The movement of carbon through ecosystems.
* Greenhouse Gases: Gases like COβ and methane that trap heat in the Earthβs atmosphere.
* Global Warming: The increase in Earth's average temperature caused by higher levels of greenhouse gases.
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GL - gav and wil
βοΈ Topic 11-27 (Chemistry all)
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Topic 11: Matter β Particle Model
1. Properties of Solids, Liquids, and Gases
* Solids, liquids, and gases are made of particles that behave differently:
* Solids: Particles are packed closely and only vibrate in place.
* Liquids: Particles are close but can move past each other.
* Gases: Particles are spread out and move freely.
* Gas Pressure: The force gas particles exert when they collide with the walls of their container.
2. Changes of State
* Changes of state happen when particlesβ movement, arrangement, and energy change.
* Melting: Solid to liquid.
* Freezing: Liquid to solid.
* Evaporation: Liquid to gas.
* Condensation: Gas to liquid.
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Topic 12: Matter β Pure Substances and Mixtures
1. Difference Between Pure Substances and Mixtures
* Pure substance: Only one type of molecule (e.g., water with only water molecules).
* Mixture: Two or more different substances mixed together (e.g., sugar water).
2. Key Terms
* Solvent: The substance that dissolves a solute.
* Solute: The substance that dissolves in the solvent.
* Solution: A mixture of solute and solvent.
* Saturated Solution: A solution that has dissolved the maximum amount of solute.
* Suspension: A mixture where small particles are dispersed in a liquid but not dissolved.
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Topic 13: Matter β Separating Mixtures
1. Methods of Separation
* Filtration: Used to separate insoluble solids from liquids (using filter paper).
* Evaporation: Used to separate a soluble solid from a solution (using heat).
* Simple Distillation: Separates a solvent from a solution (using a condenser).
* Paper Chromatography: Separates different substances in a mixture, like dyes in inks.
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Topic 14: Matter β Elements, Atoms, and Compounds
1. Meaning of Terms
* Element: A substance made of only one type of atom.
* Atom: The smallest unit of an element.
* Compound: A substance made of two or more different atoms chemically bonded.
* Molecule: Two or more atoms bonded together, either of the same or different elements.
2. Dalton's Atomic Model
* All matter is made of atoms.
* Atoms of the same element are identical.
* Atoms of different elements are different.
* Compounds are formed when atoms join together.
* Chemical reactions involve the rearrangement of atoms.
3. Common Elements and their Symbols
* Hydrogen: H
* Oxygen: O
* Nitrogen: N
* Carbon: C
* Magnesium: Mg
* Copper: Cu
* Zinc: Zn
* Aluminium: Al
* Iron: Fe
* Chlorine: Cl
* Helium: He
4. Common Molecules and their Symbols
* Hydrogen: H2
* Oxygen: O2
5. Common Compounds and their Formulae
* Carbon dioxide: CO2
* Calcium carbonate: CaCO3
* Copper carbonate: CuCO3
* Calcium chloride: CaCl2
* Copper chloride: CuCl2
* Magnesium chloride: MgCl2
* Sodium chloride: NaCl
* Zinc chloride: ZnCl2
* Copper oxide: CuO
* Magnesium oxide: MgO
* Zinc oxide: ZnO
* Water: H2O
* Hydrochloric acid: HCl
* Sodium hydroxide: NaOH
6. Chemical Reactions
* Reactions involve the rearrangement of atoms to form new substances or compounds.
* Word Equations: Describing chemical reactions using the names of the substances involved (e.g., hydrogen + oxygen β water).
7. Understanding Chemical Formulae
* A chemical formula shows the ratio of elements in a compound.
* For example, in H2O (water), the ratio of hydrogen to oxygen is 2:1.
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Topic 15: Matter β Model of an Atom
1. Structure of an Atom
* An atom is made up of three types of sub-atomic particles:
* Protons: Positively charged particles found in the nucleus.
* Neutrons: Neutral particles also in the nucleus.
* Electrons: Negatively charged particles that orbit the nucleus.
2. Relative Charges of Sub-atomic Particles
* Protons have a positive charge.
* Neutrons have no charge (neutral).
* Electrons have a negative charge.
3. Atomic and Mass Numbers
* Atomic (Proton) Number: The number of protons in the nucleus. It defines the element.
* Mass Number: The total number of protons and neutrons in an atom.
* Representation: The symbol for an atom can be written as:
a
X
b
* a = mass number
* b = atomic (proton) number
* X = symbol of the element
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Topic 16: Periodic Table β Introduction
1. Names and Chemical Symbols of Elements
* Learn the names and symbols of common elements
2. Identifying Metals and Non-metals
* Elements can be identified as metals or non-metals based on their position in the Periodic Table.
3. Physical Properties of Metals
* Electrical Conductivity: Metals can conduct electricity.
* Malleability: Metals can be hammered or pressed into shape without breaking.
4. Columns and Rows in the Periodic Table
* Groups: Vertical columns in the Periodic Table.
* Periods: Horizontal rows in the Periodic Table.
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Topic 17: Periodic Table β Arrangement of Elements and Group 1 Elements
1. Arrangement of Elements
* Elements are arranged in the Periodic Table by atomic number (the number of protons in the nucleus).
2. Groups and Periods
* Elements are organized into groups (columns) and periods (rows).
3. Reactions of Group 1 Metals with Water
* Group 1 metals, such as lithium, sodium, and potassium, react with water to produce hydrogen gas and a metal hydroxide.
* The reactions become more vigorous as you move down the group.
4. Trends in Reactions
* The reactions of Group 1 metals with water become more violent as you go down the group. This trend can be predicted using the Periodic Table.
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Topic 18: Earth and Atmosphere β Composition of Air
1. Composition of Dry Air
* Dry air consists of gases such as nitrogen, oxygen, argon, carbon dioxide, and small amounts of other gases.
* Nitrogen makes up about 78%, oxygen around 21%, and argon around 0.9%. carbon dioxide 0.04%
2. Experiments to Find the Oxygen Percentage in Air
* Experiments using iron and copper can help find the approximate percentage of oxygen in the air.
* A floating candle experiment can also give an approximate value for the oxygen content.
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Topic 19: Earth and Atmosphere β Materials Made from Substances in the Earth
1. Common Polymers and Ceramics
* Polymers:
* Poly(ethene)
* Poly(chloroethene) (PVC)
* Rubber
* Ceramics:
* Porcelain
* Pottery
* Glass
2. Uses of Polymers and Ceramics
* The uses of these materials are related to their properties (e.g., flexibility, strength, heat resistance). Students donβt need to memorize specific properties.
3. Composite Materials
* Composite materials are made by combining two or more materials, and they have some of the properties of each material.
4. Examples of Composite Materials
* Reinforced concrete
* MDF (Medium Density Fibreboard)
* GRP (Glass Reinforced Plastic)
5. Environmental Impact of Materials
* The production and use of materials, like plastics, can cause environmental problems.
* Recycling is one way to reduce these problems.
6. Biodegradable Materials
* Biodegradable materials can break down naturally in the environment.
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Topic 20: Chemical Reactions β Chemical Reactions Introduction
1. Physical Changes vs. Chemical Changes
* Physical Changes: Changes in appearance, but no new substance is formed (e.g., melting ice).
* Chemical Changes: A new substance is formed (e.g., burning wood).
2. Combustion Reactions
* Combustion is a type of reaction where a substance burns in oxygen (e.g., burning magnesium or methane).
3. Thermal Decomposition Reactions
* Thermal decomposition is when a compound breaks down into simpler substances when heated.
* Example: The thermal decomposition of copper carbonate produces copper oxide and carbon dioxide.
* Word Equation:
Copper carbonate β Copper oxide + Carbon dioxide
* Testing for Carbon Dioxide: Carbon dioxide can be tested using limewater, which turns cloudy in the presence of CO2.
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Topic 21: Chemical reactions β More on combustion
1. Products of Combustion
* An experiment can show the products of combustion of a hydrocarbon (e.g., burning a candle).
* 2. Test for Water
* Anhydrous copper(II) sulfate can be used to test for the presence of water.
* 3. Test for Carbon Dioxide
* Limewater can be used to test for the presence of carbon dioxide.
4. Causes of Air Pollution
* Air pollution can be caused by the combustion of sulfur and the complete/incomplete combustion of carbon in fossil fuels.
* Examples include the formation of soot, carbon monoxide, carbon dioxide, and sulfur dioxide.
5. Environmental Problems from Air Pollution
* Carbon dioxide is a greenhouse gas, and increasing amounts may contribute to climate change.
* * Sulfur dioxide is an acidic gas that can form acid rain, harming vegetation, aquatic life, and buildings.
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Topic 22: Chemical reactions β Energy changes in reactions
1. Exothermic Reactions
* Exothermic reactions release energy to the surroundings.
* This energy release often causes the reaction mixtureβs surroundings to get hotter.
* Example: Combustion (burning).
2. Endothermic Reactions
* Endothermic reactions absorb energy from the surroundings.
* This energy absorption often causes the reaction mixtureβs surroundings to get colder.
* Example: Thermal decomposition.
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Topic 23: Chemical reactions β Formulae and equations
1. Representing Reactions
* Simple chemical reactions can be shown using formulae and equations.
* This can include showing the state symbols:
* (s) for solid
* (l) for liquid
* (g) for gas
* (aq) for aqueous (dissolved in water)
* Examples of reactions:
* Elements reacting with oxygen (e.g., magnesium + oxygen β magnesium oxide)
* Metals reacting with dilute hydrochloric acid (e.g., magnesium + hydrochloric acid β magnesium chloride + hydrogen)
* Thermal decomposition of metal carbonates (e.g., copper carbonate β copper oxide + carbon dioxide)
2. Reactants and Products
* Reactants are the substances that react together.
* Products are the substances formed in the reaction.
3. Conservation of Mass
* Mass is conserved in chemical reactions (total mass of reactants = total mass of products).
* Some reactions may appear to lose or gain mass, like when a gas is produced and escapes.
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Topic 24: Chemical reactions β Acids, bases, and alkalis
1. Acids
* Acids have a pH less than 7.
* Acids react with metals to produce hydrogen gas and a salt.
* Acids react with carbonates to produce carbon dioxide, water, and a salt.
2. Bases and Alkalis
* Bases have a pH greater than 7.
* Alkalis are soluble bases.
* Alkalis react with acids to neutralize them and form salt and water.
3. Neutralization
* Neutralization is the reaction between an acid and a base.
* In neutralization, hydrogen ions (H+) from the acid react with hydroxide ions (OH-) from the base to form water (H2O).
4. pH Scale
* The pH scale is a measure of the acidity or alkalinity of a solution.
* pH 7 is neutral, pH less than 7 is acidic, and pH greater than 7 is alkaline.
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Topic 25: Chemical reactions β Reversible reactions and equilibrium
1. Reversible Reactions
* Reversible reactions can proceed in both forward and reverse directions.
* In a reversible reaction, reactants form products, but products can also react to reform reactants.
2. Equilibrium
* In a closed system, reversible reactions eventually reach a state of equilibrium.
* At equilibrium, the rate of the forward reaction equals the rate of the reverse reaction.
* The concentrations of reactants and products remain constant at equilibrium.
* 3. Factors Affecting Equilibrium
* Changing conditions (e.g., temperature, pressure, concentration) can shift the position of equilibrium.
* Le Chatelier's principle can be used to predict the effect of changing conditions on equilibrium.
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Topic 26: Chemical reactions β Reactivity series
1. Reactivity Series
* Metals can be arranged in a reactivity series based on their reactions with oxygen and water.
* Metals can also be arranged in a reactivity series based on their reactions with dilute hydrochloric and sulfuric acid.
2. Carbon in the Reactivity Series
* Carbon is included in the reactivity series.
* Carbon is used to obtain metals from metal oxides.
* Reduction is the loss of oxygen.
3. Displacement Reactions
* Displacement reactions involve a more reactive metal displacing a less reactive metal from its oxide or aqueous salt solution.
4. Metal Extraction
* The method of metal extraction from its ore depends on its position in the reactivity series.
* Carbon can be used to extract copper and iron, but not aluminum (for which electricity is used).
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Topic 27: Chemical reactions β Rate of reaction
1. Effect of Temperature
* Increasing the temperature generally increases the rate of a reaction.
2. Effect of Particle Size
* Decreasing the size of solid particles (i.e., increasing the surface area) increases the rate of reaction.
* Example: Hydrochloric acid reacts faster with smaller marble chips than with larger ones.
3. Effect of Collision
* Increasing the rate of collision will increase the rate of reaction.
* One way to do this is increasing the pressure
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GL - gav and wil
π§ͺ Topic 28-43 (Physics all)
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Topic 28: Energy β Energy stores and energy transfer
1. Units of Energy
* Energy is measured in joules (J) and kilojoules (kJ).
2. Energy Stores
* Energy can be stored in different ways:
* Thermal energy
* Chemical energy
* Kinetic energy
* Gravitational potential energy
* Elastic potential energy (strain energy)
* Nuclear energy
3. Energy Transfer
* Energy can be transferred between energy stores.
* No energy is created or lost (law of conservation of energy).
4. Ways of Energy Transfer
* Energy can be transferred by:
* Light waves
* Heating
* Sound waves
* Electricity
* Forces
* Energy can be wasted during transfer.
* Efficiency is a simple way to discuss wasted energy.
5. Examples of Energy Transfer
* Energy stored as gravitational potential energy can be transferred to other energy stores.
* Energy stored as elastic potential energy (strain energy) can be transferred to other energy stores.
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Topic 29: Energy β Conservation of energy
1. Law of Conservation of Energy
* Energy cannot be created or destroyed.
* Energy is only transferred from one store to another.
2. Sankey Diagrams
* Sankey diagrams are used to show energy transfers.
* These diagrams illustrate how much energy is usefully transferred and how much energy is wasted.
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Topic 30: Electricity β Electric current
1. Electric Current
* Electric current is the flow of negative charges or electrons.
* Electrons are negatively charged particles.
2. Measuring Current
* Current is measured in amperes (A).
* An ammeter is used to measure current.
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Topic 31: Electricity β Electric circuits
1. Circuit Diagrams
* Circuit diagrams use standard symbols to represent electrical circuits.
2. Series Circuits
* In a series circuit, the current flows through each component one after the other.
3. Parallel Circuits
* In a parallel circuit, the current has multiple paths to flow through.
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Topic 32: Electricity β Potential difference and resistance
1. Potential Difference
* Potential difference (voltage) is the difference in electrical potential between two points in a circuit.
* It is measured in volts (V) using a voltmeter.
2. Resistance
* Resistance is the opposition to the flow of electric current.
* It is measured in ohms (Ξ©).
3. Ohm's Law
* Ohm's Law relates potential difference, current, and resistance: V = IR
* V = potential difference (V)
* I = current (A)
* R = resistance (Ξ©)
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Topic 33: Electricity β Magnetism and electromagnetism
1. Magnets
* Magnets have a north pole and a south pole.
* Like poles repel, and opposite poles attract.
2. Magnetic Fields
* Magnets create a magnetic field around them.
* A magnetic field is the area around a magnet where a magnetic force is experienced.
3. Electromagnets
* szElectromagnets are created when an electric current flows through a wire.
* The strength of an electromagnet can be increased by increasing the current or the number of turns in the coil. You could also put a conductive core inside the coil.
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Topic 34: Waves β Wave behaviour
1. Types of Waves
* Transverse waves: The vibrations are perpendicular to the direction of energy transfer. Examples include light waves and water waves.
* Longitudinal waves: The vibrations are parallel to the direction of energy transfer. Examples include sound waves.
2. Wave Properties
* Amplitude: The maximum displacement of a wave from its rest position.
* Wavelength: The distance between two corresponding points on a wave (e.g., crest to crest or trough to trough).
* Frequency: The number of waves passing a point per second, measured in hertz (Hz).
* Wave speed: The speed at which the wave travels.
3. Wave Equation
* The wave speed (v), frequency (f), and wavelength (Ξ») are related by the equation: v = fΞ»
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Topic 35: Waves β Light waves
1. The Electromagnetic Spectrum
* Light is part of the electromagnetic spectrum.
* The electromagnetic spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
2. Properties of Light
* Light travels in straight lines.
* Light can be reflected, refracted, and diffracted.
3. Reflection
* Reflection is when light bounces off a surface.
* The angle of incidence equals the angle of reflection.
4. Refraction
* Refraction is the bending of light as it passes from one medium to another.
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Topic 36: Waves β Sound waves
1. Sound as a Wave
* Sound is a longitudinal wave.
* Sound waves require a medium to travel (e.g., air, water, solids).
* Sound cannot travel in a vacuum.
2. Speed of Sound
* The speed of sound varies in different media.
* Sound travels faster in solids than in
* liquids or gases.
3. Frequency and Pitch
* The frequency of a sound wave determines its pitch.
* Higher frequency corresponds to a higher pitch.
4. Amplitude and Loudness
* The amplitude of a sound wave determines its loudness.
* Larger amplitude corresponds to a louder sound.
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Topic 37: Forces β Forces and motion
1. Types of Forces
* Forces can affect the movement, shape, or size of an object.
2. Balanced Forces
* Balanced forces result in no change in motion.
3. Unbalanced Forces
* Unbalanced forces cause a change in motion (acceleration).
4. Friction
* Friction is a force that opposes motion.
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Topic 38: Forces β Speed
1. Speed
* Speed is a measure of how fast something is moving.
2. Calculating Speed
* Speed can be calculated using the formula: speed = distance / time
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Topic 39: Forces β Weight
1. Weight
* Weight is the force of gravity acting on an object.
* Weight is measured in newtons (N).
2. Mass
* Mass is the amount of matter in an object.
* Mass is measured in kilograms (kg).
3. Relationship between Weight and Mass
* Weight and mass are related, but they are not the same.
* Weight depends on the gravitational field strength.
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Topic 40: Forces β Moments
1. Turning Effect of Forces
* A moment is the turning effect of a force.
2. Calculating Moments
* Moment = Force x Distance from the pivot
3. Balanced Moments
* For an object to be balanced, the clockwise moments must equal the anticlockwise moments.
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Topic 41: Forces β Turning forces
1. Levers
* A lever is a simple machine that can be used to multiply force.
* Levers have a pivot (or fulcrum) around which they turn.
2. Moments
* A moment is the turning effect of a force.
* Moment = Force x Perpendicular distance from the pivot.
3. Balance
* For an object to be balanced, the total clockwise moments must equal the total anticlockwise moments.
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Topic 42: Forces β Turning forces
1. Levers
* A lever is a simple machine that can be used to multiply force.
* Levers have a pivot (or fulcrum) around which they turn.
2. Moments
* A moment is the turning effect of a force.
* Moment = Force x Perpendicular distance from the pivot.
3. Balance
* For an object to be balanced, the total clockwise moments must equal the total anticlockwise moments.
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Topic 43: Forces β Stretching forces
1. Springs
* Springs can be stretched or compressed by applying a force.
2. Elasticity
* Elasticity is the ability of a material to return to its original shape after being deformed.
3. Hooke's Law
* Hooke's Law states that the force needed to extend or compress a spring is proportional to the distance it is stretched or compressed.
* * Force = spring constant x extension (F = kx)
4. Limit of Proportionality
* The limit of proportionality is the point beyond which Hooke's Law is no longer obeyed.
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GL - gav and wil