Comprehensive High School Science Study Guide: Chemistry, Ecology, Astronomy, and Physics

Physical and Chemical Properties of Matter

• Physical Properties are characteristics of a substance that can be determined without changing the composition of the substance. These can be observed using our 5 senses.

• Examples include:

  • Colour

  • Odour

  • Taste

  • Texture

  • Malleability (the ability to mould the substance)

  • Ductility (the ability to be pulled into a finer strand)

  • Hardness (the ability to scratch other materials)

  • Optical Clarity (the ability to allow light to pass through)

  • Viscosity (the ability for a substance to resist flow)

  • Lustre (the shininess or dullness of a substance)

  • Brittleness (breakability or flexibility)

  • Electrical Conductivity (the ability to allow electric current to pass through)

  • Solubility (the ability for a substance to dissolve into another substance)

• Physical Change: A change in which the composition remains the same. No new substances are created during this process.

• Chemical Properties: A characteristic that describes the ability for a substance to undergo changes to its original composition in order to create one or more new substances.

• Examples of Chemical Properties:

  • Combustibility (reacting with oxygen to produce carbon dioxide and water)

  • Corrosiveness (the ability to eat away at skin)

  • Reaction with an acid (producing evidence of a chemical reaction after being mixed with an acid)

• Chemical Change: A change to the composition of an original substance. The original substance does not disappear; instead, its components are rearranged to produce new substances.

• Evidence of A Chemical Change includes:

  • An unexpected change in color

  • A change in odour

  • The production of a gas

  • A change in temperature

  • The formation of a precipitate

Chemical Laws and the Periodic Table of Elements

• Law of Conservation of Mass: Mass is neither created nor destroyed in a chemical reaction; the total mass of the reactants equals the total mass of the products.

• Law of Definite Proportions: A compound always contains the same elements in the same proportion by mass, regardless of the source of the compound or how it was formed.

• The First 20 Elements on The Periodic Table:

  1. H - Hydrogen

  2. He - Helium

  3. Li - Lithium

  4. Be - Beryllium

  5. B - Boron

  6. C - Carbon

  7. N - Nitrogen

  8. O - Oxygen

  9. F - Fluorine

  10. Ne - Neon

  11. Na - Sodium

  12. Mg - Magnesium

  13. Al - Aluminum

  14. Si - Silicon

  15. P - Phosphorus

  16. S - Sulfur

  17. Cl - Chlorine

  18. Ar - Argon

  19. K - Potassium

  20. Ca - Calcium

• Classifying Elements:

  • Valence electrons increase as you move across a period and stay the same as you move down a group.

  • Electron shells stay the same as you move across a period and increase as you move down a group.

Chemical Families of the Periodic Table

• Alkali Metals (Group 1):

  • Located on the far left of the periodic table.

  • Possess 1 electron in their outermost shell.

  • Highly reactive because they can easily lose their electron.

  • Shiny, silver metals that form compounds soluble in water.

• Alkaline Earth Metals (Group 2):

  • Located in the second column of the periodic table.

  • Possess 2 electrons in their outermost shell.

  • Relatively reactive.

  • Form compounds that are often insoluble.

• Halogens (Group 17):

  • Located in the second-to-last column of the periodic table.

  • Possess 7 electrons in their outermost shell.

  • Can be poisonous in large amounts.

  • React readily with alkali metals.

  • Highly reactive because they are only one electron away from having a full shell.

• The Noble Gases (Group 18):

  • Located in the furthest right column of the periodic table.

  • Possess a complete set of electrons in their outermost shell (except for He, which only has 2).

  • Non-reactive.

• Hydrogen (Group 1):

  • Possesses one electron in its only electron shell.

  • Characteristics include being colourless, odourless, tasteless, and highly flammable.

  • Has nothing in common with the alkali metals despite its position.

• Organization:

  • Periods are the horizontal rows numbered 1-7.

  • Groups are the vertical columns numbered 1-18.

Development of the Atomic Model and Structure

• The Billiard Ball Model (1807): Proposed by John Dalton. He theorized that all matter is made of tiny, indivisible particles; atoms of different elements are different; and atoms are rearranged to form different substances but are never created or destroyed.

• Thompson’s Experience - The Electron (1897): J.J Thompson discovered that very small, negatively charged particles could be emitted by very hot materials. Particles were attracted to the positive end of a circuit. He theorized that atoms contain negatively charged electrons evenly distributed throughout the atom. Since atoms are neutral, he believed the rest of the atom was positively charged.

• The Gold Foil Experiment (1909): Supervised by Ernest Rutherford to test Thompson’s model. His revised model suggested the center of the atom (nucleus) has a positive charge, contains most of the atom’s mass but occupies very little space, and is surrounded by negatively charged electrons.

• Discovery of the Proton (1920): Rutherford discovered the proton, a positively charged particle found in the nucleus. He proposed a third particle existed in the nucleus with the same mass as the proton but with a neutral charge.

• Bohr (Planetary) Model (1913): Proposed by Niels Bohr. He suggested electrons orbit the nucleus like planets. Each electron in an orbit has a definite amount of energy. Electrons cannot be located between orbits but can jump between them. Each orbit holds a maximum number of electrons (1st: 2; 2nd: 8; 3rd: 8).

• The Quantum Mechanical Model (1926): Proposed by Erwin Schrodinger. This modern theory suggests atoms are not in fixed orbits but rather in electron orbitals.

• Particle Breakdown:

  • Protons: Located in the nucleus; positive charge.

  • Electrons: Orbit the nucleus; negative charge.

  • Neutrons: Located in the nucleus; neutral charge.

  • Valence Electrons: Electrons located in the outermost shell of an atom.

• Measurements:

  • Atomic Number: The number of protons in an atom.

  • Atomic Mass: The average mass of all atoms of that element, including isotopes.

• Ions: An atom or group of atoms with an electric charge. Stable atoms must have a full outer shell (or 2 electrons for the first shell). Atoms gain or lose electrons to form ions. Chemical bonds form when atoms share or transfer electrons to achieve a stable configuration.

Chemistry in Society and the Environment

• Mercury Poisoning in Grassy Narrows: Exemplifies bioaccumulation and biomagnification.

  • Bioaccumulation: When an organism is intoxicated with toxins (like pesticides or mercury) and they slowly accumulate in the organs over time.

  • Biomagnification: When a toxin is concentrated as it moves up the food chain. Organisms at higher levels eat many of the intoxicated smaller species, magnifying the toxin levels.

• Problems with Plastics:

  • Pollutes environment during production (fossil fuels and carbon emissions).

  • Slow to decompose because the carbon bonds are different from natural chemical bonds.

  • Wildlife may mistake plastic for food.

• Solutions: Recycle, reduce single-use plastics, and buy second-hand items.

Ecology: Energy Flow and Nutrient Cycles

• Trophic Levels describe an organism's position in a food chain:

  • 1st Level: Producers (Autotrophs, like Sunflowers).

  • 2nd Level: Primary consumers (Small, eat producers).

  • 3rd Level: Secondary consumers (Eat primary consumers; can be carnivores, herbivores, or omnivores).

  • 4th Level: Tertiary consumers (Eat secondary consumers; carnivores or omnivores).

• Ecological Pyramids:

  • Energy Pyramid: Represents energy at each level. Energy decreases up the pyramid because it is used by organisms or lost to the environment. Only $10\%$ of energy is passed to the next level.

  • Number Pyramid: Shows the number of individuals in each population per level.

  • Biomass Pyramid: Shows the total mass of living organisms (biomass) in a given area per level.

• Roles:

  • Autotroph: Produces own food via photosynthesis or chemosynthesis.

  • Heterotroph: Must eat other organisms for energy (e.g., Lion).

  • Herbivore: Eats plants/producers.

  • Carnivore: Eats animals.

  • Omnivore: Eats both.

  • Scavenger: Feeds on remains of other organisms.

  • Decomposer: Breaks down dead matter.

• Food Chains and Webs:

  • Food Chain: Simple diagram of energy flow.

  • Food Web: Complex diagram showing connected food chains.

• Biological Processes:

  • Photosynthesis: Green plants, algae, and some bacteria transform light energy into chemical energy.

  • Cellular Respiration: All organisms (plants, animals, fungi, bacteria) use oxygen to break down food for chemical energy.

  • Cycle: Photosynthesis creates glucose and oxygen; cellular respiration uses these to produce carbon dioxide and water, which plants then use for photosynthesis.

• Carbon Cycle: Biogeochemical cycle where carbon moves through lithosphere, atmosphere, hydrosphere, and biosphere.

Biotic and Abiotic Influences

• Symbiotic Relationships:

  • Competition: Species vie for same resources (e.g., foxes and coyotes competing for mice).

  • Predation: Predator hunts/eats prey (e.g., Lynx and snowshoe hares).

  • Mutualism: Both benefit (e.g., Bees getting nectar while pollinating flowers).

  • Parasitism: One lives in/on and feeds on a host (e.g., Tapeworms in cats).

  • Commensalism: One benefits, the other is unaffected (e.g., Spanish moss on trees).

• Tolerance Ranges: The range of abiotic factors (temperature, light, soil) a species can survive within.

• Carrying Capacity: The maximum number of individuals of a species an environment can support over time without habitat degradation. Influenced by resource addition/removal.

• Limiting Factors: Factors that restrict population size, including predators, abiotic factors (sunlight, water), and biotic factors (food availability).

Biodiversity and Conservation

• Species at Risk Examples: Northern Wolffish, Swift Fox.

• Status Levels:

  • Extirpated: No longer exists in a specific area.

  • Endangered: Facing imminent danger of extinction or being extirpated.

  • Threatened: Likely to become endangered if current conditions persist.

  • Special Concern: May become threatened or endangered due to various factors.

• Actions: Buy local, plant gardens, reduce water waste, protect habitats.

• Invasive Species: A non-native species (introduced) whose introduction negatively impacts the environment (e.g., Asian carp, zebra mussel). Introduced species are simply non-native; they only become "invasive" if they cause harm.

• Pesticides: Chemicals designed to kill pests. Variants include herbicides and insecticides. Can lead to Bioamplification, where toxins accumulate in tissues and increase in concentration up the food chain.

• Human Impacts:

  • Clear cutting: Habitat loss, carbon emissions.

  • Overhunting: Population decline.

  • Pollution/Plastics: Chemical pollution, plastic accumulation.

  • Habitat loss: Displacement of species.

  • Oil: Spills, greenhouse gas emissions.

  • Fertilizers/Pesticides: Soil degradation.

Astronomy: Origin and Solar System

• The Big Bang Theory:

  1. The universe is $13.7 \times 10^9$ years old (13.7 billion), starting as a hot, dense ball of energy.

  2. The ball exploded/expanded, releasing building blocks of the universe.

  3. Cooling allowed energy to form subatomic particles (protons, electrons, neutrons).

  4. $300,000$ years later: Universe becomes transparent; stable atoms (Hydrogen and Helium) form and clump into galaxies.

  5. $1 \times 10^9$ years later: The oldest star formed.

• Evidence: Hubble’s discovery of the relationship between distance and speed of galaxies (1920s) and cosmic microwave background radiation (1960s).

• Planetary Order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

• Planet Categories:

  • Gas Planets (Jupiter, Saturn, Uranus, Neptune): Composed of gas or ice; large; thick atmospheres; no solid surface.

  • Terrestrial Planets (Mercury, Venus, Earth, Mars): Composed of rock and metal; smaller; thin atmospheres; solid rock surface.

• Celestial Objects:

  • Meteor: Piece of metal or rock smaller than an asteroid.

  • Meteorite: Remains of a meteoroid that landed on Earth.

  • Comets: Large chunks of ice, dust, and rock orbiting the Sun.

  • Asteroids: Small objects of rock and metal.

The Sun and Galactic Structures

• Structure of the Sun:

  • Core: Hottest part, middle of the Sun.

  • Radiative zone: Layer just outside the core.

  • Convection zone: Energy travels through gases via convection currents to the photosphere.

  • Photosphere: Surface of the sun; the coolest layer.

  • Sunspots: Darker, cooler areas on the surface.

  • Solar flares: Release gas and charged particles in active regions.

  • Solar prominence: Low energy eruptions traveling through the corona.

  • Corona: Outermost layer; visible only with special equipment.

• Effects on Earth:

  • Auroras: Caused by solar wind hitting Earth’s magnetic field.

  • Global Warming: Greenhouse gases trapping solar energy.

  • Photosynthesis: Providing energy for plants to grow and release oxygen.

• Galaxies: Collections of stars, gas, dust, and planets.

  • Spiral: Long arms, center core; arms have new stars (gas/dust); bulge has old red stars.

  • Elliptical: Spherical to egg-shaped; contains the oldest stars.

  • Irregular: No regular shape; contains both new and old stars.

Astronomical Measurements and Space Exploration

• Astronomical Unit (AU):

  • Average distance from Earth to the Sun.

  • $1\text{ AU} = 1.496 \times 10^8\,km$.

  • Used for measuring distance within the solar system.

  • Example Calculation: Measure $711,280,000\,km$ in AU.

  1. Scientific notation: $7.1128 \times 10^8\,km$.

  2. Use equation: $\frac{7.1128 \times 10^8}{1.5 \times 10^8}$.

  3. Result: $4.8 \times 10^8\text{ AU}$ (Note: value per transcript data).

• Lightyear (LY):

  • Distance light travels in one Earth year ($9.4608 \times 10^{15}\,m$).

  • Used outside the solar system.

• Applications:

  • International Space Station (ISS): Research lab built by 15 nations.

  • Canadarm (1981): Helped move large objects for ISS construction.

  • Canadarm 2: Permanently on ISS; helps catch arriving shuttles.

Physics: Static and Current Electricity

• Law of Electric Charges: Like charges repel ($- -, + +$); opposite charges attract ($+ -, - +$). Charged objects ($+$ or $-$) also attract neutral objects ($o$).

• Conductors and Insulators:

  • Good Conductors: Electrons flow easily (Copper, nickel, gold).

  • Fair Conductors: Electrons flow with difficulty (Carbon, Earth, water).

  • Insulators: Materials that do not allow easy flow.

• Methods of Charging:

  • Friction: Rubbing different materials together transfers electrons. Example: Balloon on hair. Balloon becomes $-$ and hair becomes $+$; they then stick together.

  • Conduction: Charged object touches another; electrons move from the object with more electrons to the one with fewer. Example: Shock from a doorknob.

  • Induction (Temporary): Charged object near neutral object causes an electron shift. Shift reverses when the object is removed.

  • Induction (Permanent): Results in two objects with opposite charges; involves a grounding process.

• Lightning: Wind causes electron buildup in clouds. Negative clouds repel negative charges in the ground, leaving it positive. Electrons jump to strike the ground. Lightning rods provide a safe path for flow.

• Grounding: Path for electrons to flow into or out of an "electron sink" to make an object neutral.

• Electrostatic Dusters: Use friction to build charge; dust jumps from objects to the duster.

Current Electricity and Circuits

• Current Electricity: Flow of electric charge through a conductor (unlike static electricity which does not move).

• Variables and Equations:

  • $I = \text{Current}$

  • $R = \text{Resistance}$

  • $V = \text{Voltage}$

  • $Q = \text{Charge}$

  • $T = \text{Time}$

  • Voltage: $V = IR$

  • Current: $I = \frac{Q}{\Delta T}$ or $I = \frac{V}{R}$

  • Resistance: $R = \frac{V}{I}$

• Circuits:

  • Series: Single path for electron flow.

  • Parallel: Components are on separate branches across from each other.

• Factors Affecting Resistance:

  • Temperature: Higher molecular motion leads to higher collision and higher resistance.

  • Diameter: Smaller diameter leads to less area for flow, increasing collisions and resistance.

  • Length: Longer materials increase resistance.

  • Conductivity: Better conductors have lower resistance.