Grade 9 Science Exam Review 2025 PDF

Study guide for Grade 9 Science Exam Review 2025 Chemistry  WHIMIS Symbols Symbol Name Symbol Name Why do we have WHMIS? To protect workers' health and safety. Exclamati...

Study guide for Grade 9 Science Exam Review 2025 Chemistry  WHIMIS Symbols Symbol Name Symbol Name Why do we have WHMIS? To protect workers' health and safety. Exclamati Health To ensure workplaces comply with safety on mark hazard regulations. To provide consistent information about Flame Exploding hazardous materials. over circle bomb Importance of WHMIS: Prevents injuries and illnesses. Educates workers on how to handle hazardous Gas flame materials safely. cylinder Ensures proper labeling and emergency response procedures. Skull and corrosion A legal requirement for employers. crossbone s Biohazard ous infectious materials Quantitative Properties Quantitati Property Meaning ve refers to 1.Viscosity how fast an object can flow 2.Adhestion how strong the particles of a data that substance can attract another can be substance measured 3. Cohesion how strong a substance's particles attract the same and substance’s particles expressed 4.boiling point the boiling point of an object (the in numbers. point where it heats up) 5.melting point the point when it melts 6.solubility how well something mixes 7.hardness How hard an object is 8. conductivity How easily a object lets electrons flow through it 9. density the dense an object is Qualitative Properties Qualitative Property Meaning refers to 1. Color The visual look of an object data that 2. smell an odor that comes from it describes 3. taste flavour of an object qualities or 4. state solid, liquid, gas characteristi 5. texture how it feels cs often 6. clarity transparency of an object observed 2.lustre how it shines but not 3.flexibility how bendable and how easy you can change a shape measured. 9. ductility how easy it is to make it a wire 10. malleability how easily something bends  Chemical Properties Property Meaning Chemical properties are characteristics of a substance that determine how it reacts with other substances, such as Reactivity with air How it reacts with air flammability, reactivity, and toxicity. You can tell if a chemical reaction is Reactivity with water How it reacts with water happening if there is: 1.Change in Color: A substance may Stability Its shelf life change color during a reaction. 2.Temperature Change: The reaction may release heat (exothermic) or Reactivity with other How a substance reacts to absorb heat (endothermic). substances another substance 3.Gas Production: Bubbles or fumes Reactivity with acid How a substance reacts to may form, indicating gas is produced. acid Toxicity It ability to cause harmful effects What is matter? Matter is anything that has mass and occupies space. It makes up all the physical substances in the universe, including solids, liquids, and gases. Matter is composed of atoms and molecules, which are the basic building blocks of all materials. The Particle Theory of Matter. 1. All matter consist of tiny atoms 2. All particles have space in-between them 3. Colder temps makes atoms slower 4. Particles are always attracted to each other 5. Particles are always moving they never are standing still What is the Difference Between… Element and Compound? Element Compound A pure substance made A substance can be made up of only one type of up of many types of atom. atoms. Cannot be broken down Can be broken down into into simpler substances. simpler substance. Examples: Oxygen (O), Examples: Water (H₂O), Hydrogen (H), Gold (Au). Carbon Dioxide (CO₂), Sodium Chloride (NaCl). Pure Substance and Mixture? Pure Substance Mixture Made up of only one type Contains two or more of particle (e.g., elements different substances that or compounds). are not chemically Has consistent properties bonded. throughout. Properties can vary Cannot be separated into depending on the other substances by components. physical means. Can be separated by physical means (e.g., filtration, distillation). Homogeneous Mixture and Heterogeneous Mixture? Homogeneous mixture Heterogeneous mixture The components are The components are not evenly distributed evenly distributed and can throughout. be seen as separate parts. Looks the same Has distinct, different throughout and is uniform phases or layers. in composition. Example: Salad, sand and Example: Saltwater, air. water. Compound and Mixture? Compound Mixture Made up of two or more Made up of two or more elements chemically substances (elements or compounds) physically bonded together. combined. Has a fixed composition and Has a variable composition specific chemical properties. and retains the properties of Cannot be separated by its components. Can be separated by physical physical means. means. Example: Water (H₂O), Example: Air, Salad, Sand and Carbon Dioxide (CO₂). Water. Atom and Molecule? Atom Molecule The smallest unit of an A group of two or more element. atoms chemically bonded Consists of protons, together. neutrons, and electrons. Can be made up of the Example: A single oxygen same or different atom (O). elements. Example: Water (H₂O) is a molecule made of two hydrogen atoms and one oxygen atom. Matter Classification: ATOMS AND THE PERIODIC TABLE Anatomy of an Atom Parts of Locatio Relative Electric the n mass charge atom Electron Shell 1 - Proton Nucleus Roughly + 2000 neutron Nucleus Roughly 0 2000 History of the atom Rutherford- 1911 Dalton-1808 - Discovered - Theorized the nucleus about atoms, and he thought the atm was a solid ball Thomson-1897 Bhor-1913 Bhor - Discovered used the gold the first foil experiment electrons to find the energy levels Development of the Atom. John Dalton (1803): Proposed atoms are tiny, indivisible particles, each element having unique atoms. J.J. Thomson (1897): Discovered the electron; proposed the "plum pudding model," where negative electrons are embedded in a positive sphere. Ernest Rutherford (1911): Discovered the nucleus via the gold foil experiment; proposed atoms have a dense, positively charged nucleus surrounded by empty space. Niels Bohr (1913): Proposed electrons orbit the nucleus in fixed energy levels (shells). The Periodic Table This Photo by Unknown Author is licensed under CC BY-SA Ionic compounds Formed by metals and non-metals combinding High Melting and Boiling Points Solubility in Water Conductivity Molecular compounds Low Melting and Boiling Points Poor Conductors: Varied States: Can be solids, liquids, or gases at room temperature. Less Soluble in Water Covalent Bonds Is when they share electrons How to Calculate Protons and electrons = atomic number Neutrons= atomic mass – atomic number How to draw atoms Ecology Key terms Ecosystem Components Ecosystem: A system where living organisms interact with their non-living environment. Example: A forest ecosystem includes trees (living), soil, water, and sunlight (non-living). Biotic factors: The living parts of an ecosystem. Examples: Plants, animals, fungi, bacteria. Abiotic factors: The non-living parts of an ecosystem. Examples: Water, sunlight, air, temperature, soil. Levels of Organization Species: A group of similar organisms that can reproduce with each other. Example: All tigers belong to the species Panthera tigris. Population: All members of the same species living in a specific area. Example: The deer population in a forest. Community: Different populations of species living together in the same ecosystem. Example: Deer, foxes, and oak trees in a forest. Habitats and Niches Habitat: The place where an organism lives. Example: A pond for frogs. Niche: The role or function of a species in an ecosystem. Example: Bees pollinate flowers. Earth's Spheres Lithosphere: The solid part of Earth’s surface. Atmosphere: The layer of gases surrounding Earth. Hydrosphere: All the water on Earth. Biosphere: The regions of Earth where life exists, encompassing the lithosphere, atmosphere, and hydrosphere. Producers and Consumers Producers: Organisms that make their own food through photosynthesis. Examples: Plants, algae. Consumers: Organisms that eat other organisms for energy. Example: Humans, lions. Primary Consumers: Herbivores that eat producers. Examples: Grasshoppers, rabbits. Secondary Consumers: Carnivores or omnivores that eat primary consumers. Examples: Frogs, snakes. Tertiary Consumers: Predators at the top of the food chain that eat secondary consumers. Examples: Eagles, sharks. Types of Consumers Herbivores: Animals that eat plants only. Examples: Cows, deer. Carnivores: Animals that eat other animals. Examples: Wolves, hawks. Omnivores: Animals that eat both plants and animals. Examples: Bears, humans. Scavengers: Animals that feed on the remains of dead animals. Examples: Vultures, hyenas. Decomposers: Organisms that break down organic matter and waste. Examples: Fungi, bacteria. Interactions Competition Competition occurs when two or more organisms vie for the same limited resources, such as food, shelter, water, or mates, within a habitat. predation Predation is an interaction in which one organism (the predator) hunts, kills, and eats another organism (the prey). Interactions Symbiosis A close and long-term interaction between two different species. It can be beneficial, harmful, or neutral to the species involved. Types of symbiosis Mutualism: Both species benefit. Commensalism: One species benefits, and the other is neither helped nor harmed. Parasitism: One species benefits (the parasite) while the other is harmed (the host). Ways we measure biodiversity Ecosystems Aquatic Terrestrial Carbon Cycle How humans influence the carbon cycle? Burning fossil fuels increases co2 levels in the atmosphere Deforestation reduces co2 absorbed by plants Nitrogen Cycle How humans influence the nitrogen cycle? Fertilizers nitrogen causes water pollution and eutrophication Fossil fuels emissions release nitrogen oxides causing smog and acid rain Electricity  Methods of Charging a Neutral Object Method of Definition or Charge on the Charging Description Neutral Object Rubbing two different Opposite of the Charging by materials charging friction together to material transfer electrons. A charged object touches Charging by Same as the a neutral object, contact charged object transferring Laws of electric charges. Like charges repel Neutral and charged charges attract Opposite charges attract Electrostatic Series When do we use it? To predict charges after friction. How? Grounding Electrical Discharge Definition Definition Grounding is the process Electrical discharge is the of connecting an object to sudden flow of electric the Earth, allowing excess charge between two charge to flow away and objects due to a difference neutralize the object. in charge (e.g., lightning or a spark). Ohmic Resistors Resistor that obeys Ohm law v = IR Analogy Potential Difference (Voltage): Like water pressure in a hose—it pushes the water (electric charges) through the pipe (circuit). Current: Like the flow of water in the hose—it’s the actual movement of electric charges. Resistance: Like a narrow nozzle on the hose—it restricts the flow, slowing it down. Analogy(visual) Conductors and Insulators Conductors Something that allows a current to flow through Insulators Some thing that makes it difficult for electrity to flow through Circuits(symbols) Extra part for circuits Ammeter An ammeter measures the electric current flowing through a circuit. Connected in series with load Voltmeters A voltmeter measures the potential difference (voltage) between two points in a circuit. Voltmeters go in parallel with the load  Static electricity basics What is Static Electricity? Static electricity is the build-up of electric charges on the surface of an object. It occurs when electrons are transferred from one object to another, causing one object to have an excess of electrons (negative charge) and the other to have a deficiency of electrons (positive charge). What Determines a Charge? The type of material and how easily it gains or loses electrons. Objects become charged through: Friction: Rubbing two materials transfers electrons (e.g., rubbing a balloon on hair). Contact: Touching a charged object to a neutral object transfers charge. Induction: A nearby charged object causes a redistribution of charges without direct contact. Key Concepts: Law of Electric Charges: Like charges repel (e.g., + and + or – and –). Opposite charges attract (e.g., + and –). Static charges are more likely to build up on insulators, which do not allow electrons to flow freely. Comparison of Series and Parallel Circuits Characteristic Series Circuit Parallel Circuit Number of Paths Single path for electrons to flow. Multiple paths for electrons to flow. Voltage is divided among Voltage is the same across all Voltage Across Components components (total voltage = sum of components. individual voltages). Current is divided among the Current is the same through all Current Through Components branches (total current = sum of components. currents in each branch). Increases total resistance, reducing Decreases total resistance, increasing Adding More Resistors total current. total current. If one component fails, the circuit is If one branch fails, the other Effect of a Fault broken, and all components stop branches continue working. working. Bulbs share the total voltage, so Bulbs receive the full voltage, so they Brightness of Bulbs they may be dimmer as more are maintain brightness regardless of added. how many are added. Used in devices like flashlights Used in household wiring to allow Applications where all components must work independent operation of devices together. (e.g., lights and appliances). OHM’S LAW Current, Voltage, and Resistance Current I Amperes (A) Voltage V Volts (V) Resistance R Ohms (ΩΩ)