Science Exam Notes PDF

**Science Exam notes** **[Unit 1: Science skills ]** **General lab safety rules** **Lab equipment** **[Beaker: ]** - Measure liquid or chemicals - Glass cylinder **[Erlenmeyer Flask:]**  - Measure liquids or chemicals - Heat up or burn things with flame ![...

**Science Exam notes** **[Unit 1: Science skills ]** **General lab safety rules** **Lab equipment** **[Beaker: ]** - Measure liquid or chemicals - Glass cylinder **[Erlenmeyer Flask:]**  - Measure liquids or chemicals - Heat up or burn things with flame  - Can pick up and drop liquids - Measure liquids or chemicals - Used to pour liquids into something - Powder, fine substances, and liquids - Used to scoop things  - Measures heat - Holds test tubes - Weighs items - Protects eyes - Cleans test tubes - Holds liquids, or items, or chemicals **WHMIS symbols:** - **W =** Workplace - **H =** Hazardous - **M =** Materials - **I =** Information - **S** = System - Gas under pressure, heat, may cause the container to explode, a drop or impact may cause container to explode. - Ex; Propane, Helium gas, Fire extinguisher **[Flammable]** - May burn at low temperatures, sparkles, flames, friction, may ignite it - Ex; Gasoline, OFF bug replant spray, Diesel - Speed up development of a fire and make it more intense, cause substances that do not usually burn to readily burn in air, make it last longer - Ex; Chlorine, Bleach - May cause death/toxicity with short exposure to small amount - Ex; Bleach, WD-40 - Suspected to cause serious health effects (cancer, organ damage, genetic defects) after repeated exposure - Ex; Formaldehyde, Radiation - May cause irritation to skin and eyes - Ex; Draino, Drain opener, Toilet bowl cleaner - Corrosive damage to metals, eyes, skin - Ex; Chlorine, NaOH, Bleach - May be a self-reactive substance, explosion may cause damage to surroundings - Ex; OFF bug spray, Hair spray - Organisms/toxins that ca cause disease in people or animals - Ex; Viruses, Bacteria, Mold - May cause damage to the aquatic environment or aquatic plant - Ex; Chemical spills, Pesticides **Significant figures** 1. Any digit between 1-9 is significant. Ex; 234.56 = 5 sig figs 2. A 0 at the beginning of a number is not significant. Ex; 0.02 = 1 sig fig 3. 0 between two other sig figs is significant. Ex; 503 = 3 sig figs 4. 0 at the ending is significant only if there is a decimal point. Ex; 750.0 = 4 sig figs **Rounding:** Round to 2 decimal point 3080 = 3100 **Scientific notation** 3570 = 3.57 x 10³ 0.000572 = 5.72 x 10⁻⁴ **Unit conversions** Ex; 8km/h =4.971 mi/hr 22.2 m/s 80km 1000m 1h = 22.2 m/s h 1km 3600s 1km = 1000m 1 day = 24 hours 1 minute= 60 seconds 1 mile = 1.609 kilometers 1 hour = 60 minutes **[Unit 2: Principles of Ecology]** Basic understanding of ecosystem & terms: - All the organisms in an area that interact with each other and with their environment of energy and matter. **Ecology** is the study of how living organisms interact with each otherworld and their environment. **Producers** are living things, like plants and algae, that make their own food using sunlight, water, and carbon dioxide through a process like photosynthesis. They are first on the food chain (at the bottom) **Primary consumer** are organisms that eat plants and provides that energy needed for other types of consumers to use **Secondary Consumer** are Organisms/animals that get nutritional value from eating primary consumers **Tertiary consumer** is an animal that eats primary/ secondary consumers for nutritional value (typically carnivores) **Heterotroph** is a living thing that cannot make its own food and gets energy by eating plants, animals, or other organisms. **Decomposers** are organisms that break down or eat decaying material for the energy source. They secrete enzymes. **Autotroph** is an organism that can make its own food, using light, water, carbon dioxide, etc **Herbivore** is an animal that mainly feeds on plants **Omnivore** is an animal that eats both plants and animals. **Carnivore** is an animal that mainly eats other animals. **Detritivore** is an organism that feeds on dead plants, animals, and other organic matter, helping to break it down, like worms, millipedes, or certain insects. They eat it **Scavenger** is an animal that eats dead plants or animals instead of hunting or growing its own food. Eg. Vulture They just eat it. **Consumer** is a living thing that eats plants, animals, or both to get energy because it cannot make its own food. **Biotic** are living organisms (plants, animals, fungi, bacteria) **Abiotic** refers to non-living things in the environment, like sunlight, water, air, soil, and temperature. **Habitat** is a place where an organism makes its home **Invasive species** are non -- native species being introduced into an area, causing a disruption in the ecosystem and food chain/web **Photosynthesis** is a chemical process that occurs in plants, algae, and other bacteria. It is when plants take sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar **Different def:** Photosynthesis is the process by which green plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce food (glucose) and release oxygen as an extra result. **Pyramid of energy:** The energy pyramid shows that energy decreases as you go up. Producers have the most energy, and each level above them (like herbivores and carnivores) has less. **Simpler def:** (It is the total amount of energy at each level in an ecosystem) **Pyramid of biomass:** Shows the total amount (mass) of living material at each trophic level **Trophic levels:** The position of an organism in the food chain **Food chain:** Transfer of energy from the sun to producer to primary consumer to secondary to tertiary **Food Web:** A food chain shows how energy moves from one living thing to another, starting with plants and ending with animals. **Population:** - A population is a group of the same type of organisms living in the same area at the same time. **Explain how nutrients (specifically carbon and nitrogen) cycle through an ecosystem:** - **Carbon Cycle:** Plants take in carbon dioxide (CO₂) from the air, animals eat plants, and when plants or animals die, carbon returns to the air or soil. - **Nitrogen Cycle:** Special bacteria change nitrogen from the air into a form plant can use. Plants take it in, animals eat the plants, and when they die, nitrogen goes back into the soil and air. **Factors that may disturb biogeochemical cycles include:** 1. **Pollution**: Harmful chemicals from factories and vehicles. 2. **Deforestation**: Cutting down trees reduces carbon absorption. 3. **Climate Change**: Changes in weather affect how nutrients move. 4. **Fertilizers**: Too much fertilizer adds extra nitrogen to soil. 5. **Fossil Fuels**: Burning fuels releases too much carbon. **Bioaccumulation** is the buildup of harmful substances, like pesticides or heavy metals, in an organism over time. These substances enter through food, water, or the environment and cannot easily be broken down or removed from the body. **Impact on Consumers**: - As smaller organisms with toxins are eaten by larger ones, the toxins build up more in animals higher in the food chain. - Top consumers, like humans or predators, are at the greatest risk of toxic effects. - This can lead to health problems like diseases, birth defects, or weakened immune systems **[The carrying capacity: ]** - The **carrying capacity** is the most living things an ecosystem can support without running out of food, water, or space. If there are too many, some won't survive. **[Limiting Factors: ]** Material and energy, food chains, **intra**specific competition, **inter**specific competition, density-**independent**, and density- **depend** factors **Density dependent:** factors that affect a population more as it grows larger. Examples include competition for food, water, and space, as well as disease and predation. These factors depend on how crowded a population is. **Density Independent:** factors that affect a population no matter how crowded it is. Examples include natural disasters, weather, and pollution. **Potential consequences of introducing a new species to an ecosystem:** 1. Competition: Fights for food and space with native species. 2. Predation: Eats native species. 3. Overpopulation: Grows too much without predators. 4. Ecosystem Harm: Damages habitats and resources. 5. Extinction: Native species may die out. **Human activities affect ecosystems by:** - Pollution: Harmful chemicals in air, water, and soil. - Deforestation: Cutting down trees destroys habitats. - Climate Change: Burning fossil fuels changes weather patterns. - Overhunting/Overfishing: Reduces animal populations. **What we can do:** 1. Reduce Pollution: Use less plastic and clean up waste. 2. Plant Trees: Protect forests and create new ones. 3. Save Energy: Use renewable sources like wind and solar. 4. Sustainable Practices: Hunt and fish responsibly. **[Unit 3: Chemistry in Action ]** **Element**: a substance containing only one kind of atom - Ex; Na, H₂ **Compound**: a substance made up of two or more different elements - Ex; H₂0, NO₃ **Bohr diagram** **The number of electrons, proton s, and neutrons is calculated like this:** Number of protons = atomic number Number of electrons = atomic number Number of neutrons = atomic mass -- atomic number **Lewis dot diagrams**  **Physical vs Chemical changes** - **Physical Change**: A change where the substance\'s appearance or state changes, but it remains the same substance (e.g., melting ice, cutting paper). - **Chemical Change**: A change where a new substance is formed with different properties (e.g., burning wood, rusting iron). **Cation** is when a neutral atom gives an e- away it ends up with a positive charge **Anions** are atoms that take an e- end up with a negative charge **Combining** **capacity** is the number of e- an atom must lose or gain. (= charge of ion) **Ionic compounds --** a positive ion (metal) with a negative ion (non-metal) **Ionic bond --** Formed when atoms give and take electrons. Example: Salt. **Covalent compounds** -- Formed when atoms share electrons. Example: Water.  **Polyatomic Ions** are created when two or more different nonmetals atoms form an ion. **A chemical equation** is a written representation of a chemical reaction, list reactants on the left side and products on right **1. Being able to name a compound when given formula** **Ionic compounds** **[Basic rules]** - The [metal] comes first, and we use its normal name. - The [nonmetal] comes second, but its name changes to end with "-ide" **[Examples ]** - KCl = potassium chloride (potassium combines with chlorine) - MgO = magnesium oxide (magnesium combines with oxygen) **Covalent compounds** **[Basic rules]** - Use prefixes to show. How many atoms of each element there are - The second element always ends with "-ide"  **[Examples ]** - CO**₂** = carbon dioxide (two oxygens, so "di" + "oxide") - N₂O₄ = dinitrogen tertroxide (two nitrogens, four oxygens so "di" + "tetra") **Polyatomic Ions** **[Examples ]** - NaNO₃ = sodium nitrate (sodium is the metal, and nitrate is the polyatomic ion) - CaSO₄ = calcium sulfate (calcium is the metal, and sulfate is the polyatomic ion) **2. Being able to give the formula when given the name** **Ionic compounds** - Example: NaCl = Sodium chloride **Covalent compound** - Example: H**₂**O = Dihydrogen monoxide **Polyatomic compounds** - Example: Ca(NO₃)₂ **=** Calcium nitrate **3. Being able to write formula and name compounds when given the ions** 1. - 2. - - 3. 1. - - - 2. - - - - - **The law of conservation of mass** In any chemical reaction matter cannot be created nor destroyed (rearranged to form new substances) Conservation of mass means that in chemical reactions, the total mass of the reactants equals the total mass of the products. **Chemical reaction types** Synthesis: A + B → C Decomposition: C → A + B Single displacement: A + BC → AC + B Double displacement: AB + CD → AD + BC Combustion: CxHy + O₂ → CO₂ + H₂O **Acid and bases** **Acid**: Sour (lemon), corrosive (burn), destroy bases (neutralization), conduct electricity, react with most metals (hydrogen gas is made) **Base**: Bitter (soap) DO NOT TASTE, corrosive (burn), destroy acids (neutralization), conduct electricity, feel slippery (destroy proteins and fat) **Indicator** is a substance that changes color when added to an acid or base. We often use paper containing the litmus dye as an indicator (red if it is an acid or blue if it is a base). **Ph scale** is used to test the strength of an acid or base, lower means stronger, higher means weaker, 7 means neutral. 0-6.9 is acid, 7.1-14 is base. For bases low numbers mean weak base and high number means strong base. **[Unit 4: In Motion]** - The study of matter and energy and how they interact - **Displacement**: indicates the change in position for an object.\ The shortest distance between first and final.\ **Symbol**: Δd Δ = (delta) change in.\ **Equation**: Δd = D₂ -- D₁ - **Interval of time:** the difference between two such clock readings or the duration between two events.\ **Symbol**: ΔT\ **Equation**: Time = T₂ -- T₁. Scalar quantity - **Velocity**: The speed and direction of motion. Describes how fast an object's position is changing.\ **Symbol**: **V**. Uniform motion meaning it is constant.\ **Equation**: Velocity = change in position/ change in time. **V** = Δd/ Δt. It is a vector - **Acceleration**: Describes how much an object's velocity changes in a certain time.\ **Symbol** = **a**.\ **Equation** = Acceleration = change in velocity/change in time. **A** = ΔV/ Δt. It is a vector always has the same direction as the change of velocity. **Displacement (Graph)** - Displacement (or position)- time graphs: keep track of where an object is located while it moves - \- Independent variable is plotted on the "x" axis. Example: time (it changes regardless of anything else) - \- Dependent variable is plotted on the "y" axis. Example: displacement (where the object is depends on how long it has been moving) **Newtons first law (Law of inertia)** - An object at rest or in motion will remain at rest or in motion unless there is a force acting on it. - It is friction that stops an object from moving, and not the object\'s natural tendency to stop. Without friction, the object would move forever. **Newtons 2^nd^ law** - The acceleration of an object is dependent upon two variables, the net force acting upon the object, and mass of object. **Newtons 3^rd^ law** - For every action there is an equal and opposite reaction, or for every force there is an important equal and opposite force.