Science Exam Review

🧪 CHEMISTRY FLASHCARDS

Matter

Q: What is matter?
A: Anything that has mass and takes up space.

Remember: Matter = "Mass + Space"

Examples:
✅ Water, air, desk
❌ Light, heat, sound

Particle Theory of Matter

Q: What are the 5 points?

A:

1. All matter is made of particles.

2. Particles are always moving.

3. There are spaces between particles.

4. Particles attract each other.

5. Higher temperature = faster movement.

Memory Trick: Made, Moving, Spaces, Stick, Speed

Changes of State

Change	Example
Melting	Ice → Water
Freezing	Water → Ice
Evaporation	Water → Gas
Condensation	Gas → Water
Sublimation	Solid → Gas
Deposition	Gas → Solid

---

Solids, Liquids, Gases

Solid

• Fixed shape

• Fixed volume

• Particles packed tightly

Liquid

• Takes shape of container

• Fixed volume

Gas

• No fixed shape

• No fixed volume

Memory: Solid = Stay, Liquid = Flow, Gas = Go everywhere

Pure Substance vs Mixture

Pure Substance

One type of particle

Examples:

• Gold

• Water (H₂O)

Mixture

More than one substance

Examples:

• Salad

• Salt water

Metals vs Non-metals

Metals

• Shiny

• Conduct electricity

• Malleable

Non-metals

• Dull

• Poor conductors

• Brittle

Physical Property

Can be observed without making a new substance.

Examples:

• Colour

• Density

• Melting point

• Boiling point

• Conductivity

Quantitative vs Qualitative

Quantitative

Numbers

Example:

• Mass = 20 g

Qualitative

Description

Example:

• Blue colour

Memory: Quantitative = Quantity (number)

Chemical Property

Shows how a substance reacts.

Example:

• Sodium reacts with water.

Physical vs Chemical Change

Physical Change

No new substance

Example:

• Ice melting

Chemical Change

New substance formed

Example:

• Rusting

5 Signs of Chemical Change

1. Colour change

2. Gas produced

3. Temperature change

4. Light produced

5. Precipitate formed

Memory: Color, Gas, Temp, Light, Solid

Density

Formula:

D = M ÷ V

Density = Mass ÷ Volume

⚛ PERIODIC TABLE

Element

Pure substance made of one type of atom.

Examples:

• Hydrogen

• Oxygen

• Gold

Period vs Group

Period

Rows across

Group

Columns down

Memory: Group Goes down

4 Chemical Families

Alkali Metals

• Very reactive

• 1 valence electron

Alkaline Earth Metals

• Reactive

• 2 valence electrons

Halogens

• Very reactive non-metals

• 7 valence electrons

Noble Gases

• Not reactive

• Full outer shell

Atomic Particles

Particle	Charge	Location
Proton	+	Nucleus
Neutron	0	Nucleus
Electron	-	Electron shell

Memory: P+ N0 E-

Atomic Number

= Number of Protons

Mass Number

= Protons + Neutrons

Valence Electrons

Electrons in the outer shell.

They determine how atoms react.

🧬 ELEMENTS & COMPOUNDS

Atom vs Molecule

Atom

Single particle

Example:

• H

Molecule

Atoms joined together

Example:

• H₂O

Element vs Compound

Element

One type of atom

Example:

• O₂

Compound

Different atoms bonded

Example:

• H₂O

7 Diatomic Elements

HOFBrINCl

Hydrogen
Oxygen
Fluorine
Bromine
Iodine
Nitrogen
Chlorine

Common Formulas

Hydrogen Gas = H₂

Oxygen Gas = O₂

Nitrogen Gas = N₂

Carbon Dioxide = CO₂

Water = H₂O

Glucose = C₆H₁₂O₆

Ionic vs Covalent

Ionic

Metal + Non-metal

Electrons transferred

Example:
NaCl

Covalent

Non-metal + Non-metal

Electrons shared

Example:
H₂O

⚡ ELECTRICITY

Static Electricity

Build-up of charges.

Law of Electric Charges

Opposites attract

Likes repel

Charging Methods

Friction

Rubbing

Conduction

Touching

Induction

No touching

Conductors vs Insulators

Conductors

Allow electricity through

Examples:

• Copper

• Aluminum

Insulators

Block electricity

Examples:

• Rubber

• Plastic

Electric Current

Flow of electrons.

Symbol = I

Unit = Ampere (A)

Voltage

Push that moves electrons.

Symbol = V

Unit = Volt (V)

Ammeter

Measures current.

Connected in SERIES.

Voltmeter

Measures voltage.

Connected in PARALLEL.

Series vs Parallel Circuits

Series

One path

If one bulb goes out → all go out

Parallel

Multiple paths

If one bulb goes out → others stay on

Homes use Parallel Circuits

Ecology & Ecosystems

Ecology

The study of interactions between living things and their environment.

Ecosystem

A community of organisms and the non-living environment they interact with.

Example: Forest, pond, grassland

Biotic vs Abiotic

Biotic = Living

Examples:

• Plants

• Animals

• Fungi

• Bacteria

Abiotic = Non-living

Examples:

• Water

• Sunlight

• Temperature

• Soil

Terrestrial vs Aquatic Ecosystems

Terrestrial (Land)

Examples:

• Forest

• Desert

• Grassland

Aquatic (Water)

Examples:

• Ocean

• Lake

• River

Levels of Ecological Organization

Smallest → Largest

1. Individual

2. Population

3. Community

4. Ecosystem

5. Biome

6. Biosphere

Earth's Spheres

Atmosphere

Air

Hydrosphere

Water

Lithosphere

Rock and soil

Biosphere

All living things

Sustainability

• Using resources so they don’t run out

• Example

Planting trees after cutting some down.

Photosynthesis

Plants make food using sunlight.

Word Equation

Carbon Dioxide+Water+Light Energy→Glucose+OxygenCarbon Dioxide+Water+Light Energy→Glucose+Oxygen

Memory Trick

Plants take in:

• CO₂

• Water

• Sunlight

Plants produce:

• Sugar

• Oxygen

Cellular Respiration

Organisms release energy from food.

Word Equation

Glucose+Oxygen→Carbon Dioxide+Water+EnergyGlucose+Oxygen→Carbon Dioxide+Water+Energy

Memory Trick

Photosynthesis stores energy.
Respiration releases energy.

Producers vs Consumers

Producers (Autotrophs)

Make their own food.

Examples:

• Trees

• Grass

• Algae

Consumers (Heterotrophs)

Eat other organisms.

Examples:

• Deer

• Wolf

• Human

Consumer Types

Herbivore

Eats plants

• Rabbit

Carnivore

Eats animals

• Wolf

Omnivore

Eats both

• Bear

• Human

Scavenger

Eats dead organisms

• Vulture

Decomposer

Breaks down dead matter

• Fungi

• Bacteria

Food Chain vs Food Web

Food Chain

One pathway of energy flow.

Grass → Rabbit → Fox

Food Web

Many connected food chains.

More realistic.

Trophic Levels

Level 1 = Producers

Level 2 = Primary Consumers

Level 3 = Secondary Consumers

Level 4 = Tertiary Consumers

Level 5 = Quaternary Consumers

Energy Pyramid

Only about 10% of energy passes to the next level.

Why?

Energy is lost as:

• Heat

• Movement

• Waste

Memory Trick

90% lost, 10% passed

Water Cycle

• Evaporation

• Condensation

• Precipitation

• Collection

Carbon Cycle

Photosynthesis

Plants remove CO₂.

Cellular Respiration

Living things release CO₂.

Decomposition

Dead organisms release carbon.

Combustion

Burning fuels releases CO₂.

Human Impacts on Carbon Cycle

• Burning fossil fuels

• Deforestation

• Industry

• Transportation

Result

More CO₂ → Climate change

Reduce Your Carbon Footprint

• Walk or bike

• Use public transit

• Turn off lights

• Reduce waste

• Recycle

• Plant trees

Nitrogen Cycle

Nitrogen Fixation

Bacteria convert nitrogen gas into usable forms.

Producers

Absorb nitrates.

Consumers

Eat plants/animals.

Decomposers

Return nitrogen to soil.

Denitrifying Bacteria

Return nitrogen to atmosphere.

Limiting Factors

Anything that limits population growth.

Examples:

• Food

• Water

• Space

• Sunlight

Density-Dependent Factors

Effects increase as population increases.

Examples:

• Disease

• Competition

• Predation

• Parasitism

Memory Trick

More organisms = bigger effect

Density-Independent Factors

Affect populations regardless of size.

Examples:

• Floods

• Fires

• Droughts

• Hurricanes

Symbiosis

Mutualism

Both benefit.
Bee + Flower

Commensalism

One benefits, other unaffected.
Barnacle + Whale

Parasitism

One benefits, one harmed.
Tick + Dog

Carrying Capacity

Maximum population an environment can support.

Symbol often shown as:
K

Ecological Succession

Primary Succession

Starts with no soil.
Example: Bare rock after volcano.

Secondary Succession

Soil already exists.
Example: Forest after fire.

Biodiversity

Variety of living things in an area.

Importance

• Stable ecosystems

• Food sources

• Medicines

• Healthy environments

Extinct, Extirpated, Threatened, Endangered

Extinct

Gone everywhere.

Extirpated

Gone from one area but exists elsewhere.

Threatened

Likely to become endangered.

Endangered

At risk of extinction.

Invasive Species

Non-native species that cause harm.

Examples:

• Zebra mussels

• Emerald ash borer

Effects

• Compete with native species

• Spread disease

• Damage ecosystems

Controlling Invasive Species

Mechanical

Remove by hand/traps.

Chemical

Use pesticides/herbicides.

Biological

Introduce natural predators.

Pollutants

Harmful substances released into environment.

Examples:

• Smoke

• Plastic

• Oil spills

• Pesticides

Acid Rain

Cause

Sulfur dioxide (SO₂) and nitrogen oxides (NOx) reacting with water in the atmosphere.

Effects

• Damages forests

• Harms lakes

• Corrodes buildings

Prevention

• Reduce emissions

• Cleaner energy

• Public transportation

Fertilizers

Add nutrients to soil.

Natural

Manure, compost

Synthetic

Human-made chemicals

Pesticides

Chemicals used to kill pests.

Types

• Herbicides → plants

• Insecticides → insects

• Fungicides → fungi

Bioaccumulation vs Biomagnification

Bioaccumulation

Toxins build up in one organism.

Biomagnification

Toxin concentration increases higher in food chain.

Memory Trick

Bioaccumulation = one organism
Biomagnification = many trophic levels

Natural vs Artificial Ecosystems

Natural

Occurs naturally.

• Forest

• Wetland

Artificial

Created by humans.

• Farm

• Aquarium