Science EOY Notes
1. Safety, Science, and Equipment
Lab Safety Rules
Always wear goggles and lab coats.
Tie back long hair and secure loose clothing.
No eating, drinking, or horseplay in the lab.
Report spills and accidents immediately.
Common Laboratory Equipment
Beakers & Flasks: Used to hold, mix, and heat liquids.
Bunsen Burner: Provides a controlled flame for heating substances.
Test Tubes & Pipettes: For measuring and transferring small amounts of liquids.
Microscopes: For examining tiny specimens at high magnification.
2. Food, Nutrition, and Energy
Food Groups
Carbohydrates: Primary energy source (e.g., bread, pasta).
Proteins: Build and repair tissues (e.g., meat, beans).
Fats: Provide energy and insulation (e.g., butter, oils).
Vitamins & Minerals: Essential for body functions (found in fruits and vegetables).
Dairy: Source of calcium and other nutrients.
Balanced Diet
Consumes a variety of foods from all food groups.
Supplies the body with energy, vitamins, and minerals in the right proportions.
Calculating Energy in Foods
Measurement Units: Energy is often measured in kilojoules (kJ) in the UK (or calories).
Macronutrient Values:
Carbohydrates and proteins provide roughly 17 kJ (4 calories) per gram.
Fats provide about 37 kJ (9 calories) per gram.
Use these values to estimate the energy provided by a given food.
Types of Food
Can be categorised as natural (fresh fruits, vegetables) or processed (ready meals, packaged snacks).
Understanding food types helps in making healthy choices.
3. Biological Structures and Processes
Bone Structures
Bones give the body structure and protect vital organs.
They store minerals like calcium and produce blood cells.
Respiration (Aerobic Respiration)
Uses oxygen to convert sugars into energy (ATP) in cells.
Produces carbon dioxide and water as waste products.
Takes place in the mitochondria.
Smoking
Introduces harmful chemicals (e.g., tar, nicotine) that damage lung tissue and hinder respiration.
Can affect overall health by reducing oxygen absorption.
Digestion and Related Processes
Digestion: The breakdown of food into simpler substances for absorption.
Enzymes: Biological catalysts (e.g., amylase) that speed up chemical reactions in digestion.
Villi: Tiny finger-like projections in the intestines that increase the surface area for nutrient absorption.
Bacteria:
Probiotics: Beneficial bacteria that aid digestion.
Prebiotics: Non-digestible substances that support the growth of good bacteria.
4. Matter: States, Substances, and Materials
States of Matter
Solids: Have a fixed shape and volume.
Liquids: Have a fixed volume but take the shape of their container.
Gases: Have neither fixed shape nor fixed volume.
Substances, Mixtures, and Compounds
Pure Substances: Have a constant composition (elements or compounds).
Compounds: Chemically combined elements (e.g., water = H₂O).
Mixtures: Physically combined substances that can be separated (e.g., salad, sandy water).
Compound Materials vs. Composite Materials
Compound Materials: Are pure substances, where elements are combined in fixed ratios.
Composite Materials: Made by combining two or more materials to enhance strength (e.g., fiberglass, where glass fibers are set in a resin).
Polymers and Monomers
Monomers: Small molecules that serve as the building blocks.
Polymers: Long chains of monomers (e.g., plastics).
Fiberglass: A type of composite material, combining glass fibers with plastic resin.
5. Atoms, Chemical Reactions, and Equations
Atomic Structure and Orbits
Atoms consist of a nucleus (protons and neutrons) with electrons orbiting in energy levels.
The Bohr model shows electrons in defined orbits around the nucleus.
Balanced Equations
Chemical equations must have equal numbers of each type of atom on both sides to obey the law of conservation of mass.
Chemical Reactions: Exothermic vs. Endothermic
Exothermic Reactions: Release energy (heat or light), such as combustion.
Endothermic Reactions: Absorb energy from the surroundings.
Combustion, Decomposition, and Oxidation
Combustion: A rapid form of oxidation producing heat and light.
Decomposition: The breakdown of compounds into simpler substances.
Oxidation Reactions: Involve the loss of electrons (e.g., rusting of iron).
6. Materials and Energy Sources
Metals and Non-Metals
Metals: Typically shiny, good conductors of heat and electricity, malleable and ductile.
Non-Metals: Diverse in appearance, often poor conductors, and can be solids (like sulfur), liquids, or gases.
Alloys
Mixtures of metals (or metals with other elements) that have properties different from their components (e.g., steel, brass).
Non-Renewable vs. Renewable Energy
Non-Renewable: Energy sources that cannot be replenished in a short time (e.g., oil, coal, gas).
Renewable: Energy sources that are naturally replenished (e.g., solar, wind, tidal).
Upthrust (Buoyant Force)
The upward force exerted by a fluid that opposes the weight of an object immersed in it.
Determined by the volume of the object and the density of the fluid.
Rust
The product of the oxidation of iron, forming iron oxide.
Occurs in the presence of water and oxygen.
7. Motion, Forces, and Mechanics
Basics of Force and Newtons
Force: A push or pull acting on an object, measured in newtons (N).
Newton’s laws describe how forces cause changes in motion.
Speed, Distance, and Time Graphs
Speed: Calculated as distance divided by time (Speed = Distance/Time).
Graphs help visualize how speed changes with time.
Drag, Air Resistance, and Friction
Drag: The resistive force air or fluid exerts on a moving object.
Air Resistance: A specific type of drag encountered in the atmosphere.
Friction: The resistance between two surfaces in contact.
Contact vs. Non-Contact Forces
Contact Forces: Involve physical contact (e.g., friction, tension).
Non-Contact Forces: Act at a distance (e.g., gravity, magnetic forces).
Muscles, Antagonistic Pairs, and Human Movement
Muscle Pairs: For every movement, an agonist (contracting muscle) is balanced by an antagonist (relaxing muscle).
Examples include the biceps (flexors) and triceps (extensors) around the arm.
Acceleration and Deceleration
Acceleration: The rate of change of velocity (speeding up).
Deceleration: The rate of slowing down.
Graphs of velocity versus time illustrate these changes.
Unbalanced vs. Balanced Forces
Unbalanced Forces: Cause changes in the state of motion (acceleration).
Balanced Forces: Cancel each other out, resulting in no change in motion.
Hooke's Law
Describes the behavior of springs: Force (F) is proportional to the displacement (x), following the formula F = kx, where k is the spring constant.
8. Acids, Bases, and pH
Acids and Alkalis (Bases)
Acids: Substances that donate hydrogen ions (H⁺) and have a pH less than 7 (e.g., lemon juice).
Alkalis (Bases): Substances that donate hydroxide ions (OH⁻) and have a pH greater than 7 (e.g., baking soda solution).
pH Scale
Ranges from 0 (highly acidic) to 14 (highly alkaline); 7 is neutral.
Neutralisation Reactions
Occur when an acid reacts with a base to form a salt and water, moving the pH closer to neutral.
9. Sound and Light
Sound, Vacuums, and the Ear
Sound: Vibrations that travel through a medium (gas, liquid, or solid); cannot travel through a vacuum.
Ear Structure: Consists of the outer ear (collects sound), middle ear (ossicles transmit vibrations), and inner ear (converts them to nerve impulses).
Echoes, Echolocation, and Ultrasound
Echoes: Reflected sound waves that return to the source, sometimes used to determine distance.
Echolocation: A technique used by animals (like bats) to navigate by interpreting echoes.
Ultrasound: High-frequency sound waves used in medical imaging.
Light: Luminescence and Optical Phenomena
Luminescent Materials: Emit light after absorbing energy (e.g., glow sticks).
Non-Luminescent Materials: Reflect or absorb light without emitting it.
Ray Diagrams: Visual tools to trace the path of light through systems.
Shadows: Form when an opaque object blocks light.
Reflection: The bouncing back of light from a surface.
Refraction: The bending of light as it passes from one medium to another (e.g., air to water).
Colours: Determined by the wavelength of light; the human eye perceives different wavelengths as different colours.
The Human Eye
Key Parts:
Cornea: The clear front layer that helps focus light.
Iris and Pupil: Control the amount of light entering the eye.
Lens: Focuses light onto the retina.
Retina: Contains light-sensitive cells that convert light into nerve signals.
These notes are designed to be bite-sized and modular, which will make it easier to transform each bullet point into individual flashcards in Knowt. For example, a flashcard might feature:
Front: "What are the three states of matter and their key characteristics?"
Back: "Solids – fixed shape and volume; Liquids – fixed volume, take the shape of their container; Gases – no fixed shape or volume."
Or another:
Front: "Explain Hooke's Law."
Back: "Hooke’s Law states that the force required to extend or compress a spring is proportional to the distance moved (F = kx), where k is the spring constant."