PLANET EARTH
8ESp.01 Know that the reason the Earth has a magnetic field is that the core acts as a
magnet.
Reference(s): Google classroom
Note: skipping the main points on magnets bc we learned that in g7 and I just cant
bother
● Caused by an dynamo effect
○ Because the earth’s core is made out of liquid & nickel
○ Liquid metal from the outer core (fluid motions)
○ Generates electric current
○ Sustained by convection currents, driven by buoyancy
○ The Earth's rotation influences the flow of the molten metals, causing
them to swirl in a particular pattern.
■ Dynamo light in bikes
● When you pedal the bike the magnets in the dynamo starts
spinning, creating an electric current, creating light
● Convection currents
○ In the outer core, the molten iron and nickel move due to heat convection.
The intense heat from the inner core causes the molten metals in the
outer core to rise, cool slightly as they approach the mantle, and then sink
again in a cycle.
Extra: North -> South
QUESTIONS
Q: If one end of a bar magnet is dipped into a pot of iron filings and raised up, the iron
filings form spiky columns in all directions. Why do they do this?
A: because the lines of force are not only 2D but also 3D.
Q: What sort of compass is used to investigate magnetic fields?
A: plotting compass
8ESp.02 Identify renewable resources (including wind, tidal and solar power, and
bioplastics) and non-renewable resources (including fossil fuels), and describe how
humans use them.
Reference(s): Google classroom
● Renewable resources
○ Restores naturally at a rate comparable of human consumption
■ Agricultural Products: Crops and livestock regenerate seasonally
or annually. Wild food sources are also renewable with
management.
■ Solar Energy: Energy from the sun.
■ Wind Energy: Energy from wind.
■ Hydropower: Energy from the movement of water in rivers,
streams, or dams.
■ Biomass: Organic material from plants and animals used as fuel.
■ Geothermal Energy: Heat from the Earth’s interior.
■ Tidal Energy: Energy from the movement of tides, a form of
hydropower.
■ Wave Energy: Energy from the surface motion of oceans or lakes.
■ Biofuels: Fuels from organic materials, such as ethanol and
biodiesel.
■ Ambient Heat: Energy from the air or water temperature
differences in the environment.
● Non-renewable resources
○ Exist in limited quantities or replenish over geological time spans
■ Coal: A fossil fuel primarily for electricity generation and industrial
processes.
■ Crude Oil: A liquid fossil fuel that yields gasoline, diesel, and other
petroleum products.
■ Natural Gas: A gaseous fossil fuel consisting primarily of methane,
used for heating, cooking, and electricity generation.
■ Nuclear Energy: Comes from the nuclear reactions of elements like
uranium. Note this applies to fission. Fusion is theoretically a
renewable form of nuclear energy. Power from radioactive decay
isn’t renewable, exactly, but some decay processes occur over
thousands, millions, or billions of years.
■ Minerals: Such as gold, silver, and copper, which are mined from
the Earth.
■
●
●
Metal Ores: Iron, aluminum, and zinc ores which are extracted and
refined.
Water as a renewable resource
○ It goes through a continuous process of evaporation, condensation, and
precipitation (the hydrological cycle), which replenishes freshwater
sources such as rivers, lakes, and aquifers over time. This cycle is powered
by the sun, and as long as the sun shines, the water cycle will continue.
Water as a non-renewable resource
○ Overuse of Groundwater: In some areas, groundwater extraction is
faster than the rate at which it replenishes naturally. This is common in
agricultural and densely populated regions. When aquifers deplete faster
than they recharge, water is effectively nonrenewable.
○ Pollution: Water contaminated by pollutants becomes unusable. If the
contamination is severe and persistent, the affected water source is
nonrenewable since it cannot be naturally cleaned and replenished at a
viable rate.
○ Climate Change and Drought: Climate change alters weather patterns,
leading to droughts in areas that previously had abundant water. This
turns previously renewable sources of water into nonrenewable ones, at
least temporarily.
○ Geographical Limitations: In certain arid regions, the natural
replenishment of water sources is extremely limited. In these areas, the
availability of naturally occurring fresh water is so low that it functions
more like a nonrenewable resource.
1. Environmental Impact:
●
●
Renewable Energy: Generally has a lower environmental impact. For example,
solar and wind power produce no greenhouse gas emissions during operation.
However, their production and disposal has environmental effects.
Nonrenewable Energy: Typically has a significant environmental impact,
particularly fossil fuels, which are major sources of greenhouse gas emissions
and pollution.
2. Infrastructure Requirements:
●
Renewable Energy: Requires significant infrastructure investment, such as wind
farms or solar panels. Some renewable sources are also location-dependent.
●
Nonrenewable Energy: Established infrastructure in most places, but extraction
and transportation are challenging and environmentally damaging.
Cases Where Renewable Energy Is Not “Greener”
●
●
●
Biomass Energy: Leads to deforestation and increase in carbon emissions if not
managed sustainably.
Hydropower: Large dams disrupt ecosystems and displace communities.
Solar Panels and Wind Turbines: Their production involves energy-intensive
processes and materials that are harmful if not disposed of properly. Wind
turbines also pose risks to wildlife.
Pros of Renewable Energy:
1.
2.
3.
4.
Sustainable and inexhaustible.
Lower greenhouse gas emissions.
Reduced dependence on fossil fuels.
Potential for local job creation.
Cons of Renewable Energy:
1.
2.
3.
4.
Higher initial costs.
Intermittency issues (e.g., solar energy is not produced at night).
Requires large areas for some technologies.
Environmental impact in manufacturing and disposal.
Pros of Nonrenewable Energy:
1. Reliable and consistent energy supply.
2. Established infrastructure and technology.
3. Lower initial investment in many cases.
Cons of Nonrenewable Energy:
1.
2.
3.
4.
Finite and unsustainable in the long term.
Significant environmental pollution and greenhouse gas emissions.
Health risks associated with pollution.
Vulnerable to market and geopolitical fluctuations.
8ESc.01 Understand that there is evidence that the Earth's climate exists in a cycle
between warm periods and ice ages, and the cycle takes place over long time periods.
8ESc.02 Understand that the Earth's climate can change due to atmospheric change.
9ESc.02 Describe the historical and predicted future impacts of climate change,
including sea level change, flooding, drought and extreme weather events.
Reference(s): Youtube, Docs
● Evidence. How do we know the climate a million years ago when simple
technology didn't exist?
○ Through comparing and combining natural resources
■ Ice cores
■ Ocean sediments
■ Sedimentary rocks
● When rocks are exposed to the surface, erosion takes place
and this breaks the rock down to smaller pieces and these
pieces are carried away by the water and wind. In time it’ll
form a sedimentary layer which will later form to
sedimentary rocks.
● This sedimentary rocks can be used to determine how the
climate was when the erosion took place.
● Different sized in of fragments indicates change in sea level
● Sandstone constrain iron oxide which makes them red and
indicate that the climate was hot
■ Fossil
● Plants and animals need certain conditions to survive and if
the climate doesn’t meet the requirement, they will go
extinct and form fossils. -> Climate change
■ Pollen grains
● The coat of pollen grain is made of tough material that can
preserve sedimentary rocks or ice. Different layers can
describe the climate when the layer was formed
■ Ice cores
● Drilling into the ice and drawing out a long piece of ice.
Pollen grains, dust, can be found.
● Carbon dioxide levels have a direct relationship with the temperature over the
years
○ It’s currently the highest its been in a million years
●
●
○ This makes the climate as hot as its been since it last left the ice age
Sea level have a direct relationship with the temperature over the years
○ As the earth left the ice age, sea levels increase by tens of meters (enough
to reshape the earth)
○ Because a hotter planet means more ice melting -> more water +
expansion of oceans
○ IMPORTANT NOTE ABOUT THE RELATIONSHIP: When the temperature
stabilizes, it takes the ice and ocean a while to equilibrium.
Atmospheric change
○ Greenhouse gasses (Co2)
○ Water vapor positive feedback loop
■ Water vapor doesn't directly increase because of human activities
like CO₂ does. Instead, it increases as a result of the warming
caused by CO₂ and other greenhouse gases.
■ Greenhouse gasses (co2) -> more heat in the atmosphere ->
increase of evaporation in bodies of water (lakes, oceans, etc) ->
water vapor -> absorbs more heat
○ Natural Atmospheric Changes
■ Volcanic eruptions
■ Solar Radiation Variations: Changes in the sun's energy output
○ Aerosols: Tiny particles
■ Reflect sunlight and cool the Earth's surface.
■ Sea spray
■ mineral dust
■ Smoke
■ volcanic ash
Temperature a million years ago changed due to the earth spinning differently,
meaning some parts that used to get a lot of sunlight no longer got a lot of
sunlight. This caused the natural part of the cycle.
In summary, we are now in an interglacial period that has lasted for over 11,000 years.
Historically, Earth's natural cycles suggest that another ice age could eventually occur,
though human activities such as the burning of fossil fuels have raised atmospheric CO₂
levels and may be delaying or altering the timing of these natural cycles.
●
While these cycles have been a natural part of Earth's climate history, human-induced
climate change is adding a new, rapid warming factor to the system that is occurring
over decades and centuries, much faster than the natural glacial-interglacial cycles.
8ESc.03 Describe the difference between climate and weather.
● Weather
●
○ Short-term changes in the atmosphere
Climate
○ Atmospheric changes over longer periods of time
9ESp.01 Explain the movement of tectonic plates in terms of convection currents.
● Convection currents
○ In the outer core, the molten iron and nickel move due to heat convection.
The intense heat from the inner core causes the molten metals in the
outer core to rise, cool slightly as they approach the mantle, and then sink
again in a cycle.
●
●
●
Convergent boundaries
○ boundaries may crash into each other
○ one boundary goes underneath the other
○ can cause earthquakes as boundaries of the two plates to collide
Divergent boundaries
○ boundaries may move apart
○ hot runny rock in the mantle pushes its way up through the crust and
spreads out on each side of the boundary
○ the magma will freeze on either side of the boundary if it happens in the
ocean.
Transform boundaries
○ boundaries may slide by, next to each other
○ they vibrate and cause earthquakes
○ many happens under the oceans, but some are found on land
○ San Andreas fault-line in North America is one example
9ESp.02 Explain why the jigsaw appearance of continental coasts, location of
volcanoes and earthquakes, fossil record and alignment of magnetic materials in the
Earth's crust are all evidence for tectonic plates.
● Jigsaw appearance
● Volcanoes
○ Most volcanoes are located at the edge of the boundaries
■ Pacific plate, in a region called the Ring of Fire
● Earthquakes
○ Most earthquakes happen at the boundaries of the tectonic plates
○ The locations of volcanoes and earthquakes directly correspond to the
edges of tectonic plates, showing that these geological phenomena are
linked to plate movements.
● Fossil record
Fossils of the same species of ancient plants and animals have been
found on continents that are now widely separated by oceans.
■ Mesosaurus: A freshwater reptile whose fossils are found in both
South America and Africa, even though it could not have swum
across the Atlantic Ocean.
■ Glossopteris: A fern-like plant whose fossils are found in South
America, Africa, Antarctica, and India.
○ The presence of identical or similar fossils on continents separated by
oceans supports the idea that these continents were once connected and
part of a single landmass before tectonic plates moved them apart.
Alignment of magnetic materials
○ As molten rock (magma) rises from mid-ocean ridges and solidifies to
form new oceanic crust, iron-rich minerals within the rock align
themselves with the Earth's magnetic field. Over time, Earth's magnetic
field has reversed many times, causing the iron minerals to record
alternating patterns of normal and reversed polarity.
○ The magnetic alignment in the oceanic crust provides evidence for the
movement of tectonic plates and shows that new crust is generated at
divergent boundaries, pushing older crust away from the ridges.
○
●
9ESc.01 Describe the carbon cycle (limited to photosynthesis, respiration, feeding,
decomposition and combustion).
Reference(s): Site
● Carbon cycle
○ Carbon present in the atmosphere is absorbed by plants. (photosynthesis)
○ These plants are then consumed by animals and carbon gets bio
accumulated into their bodies. (feeding: when animals go nom nom on
food)
○ These animals and plants eventually die, and upon decomposing, carbon
is released back into the atmosphere. (decomposing)
○ Some of the carbon that is not released back into the atmosphere
eventually becomes fossil fuels.
○ These fossil fuels are then used for man-made activities, which pump
more carbon back into the atmosphere. (combustion: burning fossil fuels
which releases carbon that had been stored underground back into the
atmosphere as CO₂)
●
●
●
Carbon cycle on land
○ CO2 (Carbon dioxide)
○ Enters naturally to the atmosphere through respiration and industrial
applications such as burning fossil fuels.
○ CO2 + H2O + energy → (CH2O)n +O2
Carbon cycle in the ocean
○ The oceanic carbon cycle involves the sea absorbing more carbon than it
releases, making it a "carbon sink." Marine organisms use carbon to form
calcium carbonate shells. When these organisms die, their shells
accumulate on the seafloor, eventually forming limestone under
pressure.Limestone is exposed to air weathers, releasing carbon dioxide
back into the atmosphere.
Key points on carbon cycle
○ Carbon cycle explains the movement of carbon between the earth’s
biosphere, geosphere, hydrosphere and atmosphere.
○ Carbon is an important element of life.
○ Carbon dioxide in the atmosphere is taken up by green plants and other
photosynthetic organisms and is converted into organic molecules that
travel through the food chain. Carbon atoms are then released as carbon
dioxide when organisms respire.
○ The formation of fossil fuels and sedimentary rocks contributes to the
carbon cycle for very long periods.
○ The carbon cycle is associated with the availability of other compounds as
well.
BEYOND THE EARTH
8ESs.01 Describe a galaxy in terms of stellar dust and gas, stars and planetary
systems.
8ESs.02 Describe asteroids as rocks, smaller than planets, and describe their formation
from rocks left over from the formation of a planetary system.
● The Milky Way
-Produced by huge numbers of stars
-The astronomical term for groups of stars in space is galaxy - milky way is a galaxy
-Stars are arranged in a spiral
-About 100 000 light years and rotate at 270 km/s
Galaxies
● Formed by stellar dust, stars and planetary system - all held together by gravity
● Distant galaxies
Science in Context
● Ernest Hubble discovered that some of the gas clouds were vast groups of stars
outside the Milky Way.
These vast groups of stars are separate galaxies
● Three types of Galaxy
○ Spiral galaxy
○ Elliptical galaxies
○ Irregular galaxies
-Galaxies moving through space can sometimes crash into one another, this can cause
it’s shape to change or they merge together to form a new galaxy.
● Intergalactic Space
-Galaxies is separated from each other by the intergalactic space
-It is almost a complete vacuum
● Stellar Dust
-Tiny solid particles that can be found in the galaxy.
-It can also be called interstellar dust or cosmic dust
-It is produced by stars
● Clouds in galaxy
-Gases and cosmic dust form huge clouds inside the galaxies
● Planetary system
-Has a star in the center and other planets that revolve around it, moons, asteroids ,
dwarf planets, comets, etc.
-Planes that orbits around a star that is not a sun are called exoplanets
●
Asteroids
○ Small rocky object that orbits the sun.
○ There is an asteroid belt around between mars and jupiter
9ESs.01 Describe the consequences of asteroid collision with the Earth, including
climate change and mass extinctions.
9ESs.02 Describe the evidence for the collision theory for the formation of the Moon.
9ESs.03 Know that nebulae are clouds of dust and gas, and can act as stellar nurseries.
TEST B
8Bp.01 Identify the constituents of a balanced diet for humans as including protein,
carbohydrates, fats and oils, water, minerals (limited to calcium and iron) and vitamins
(limited to A, C and D), and describe the functions of these nutrients.
8Bp.02 Understand that carbohydrates and fats can be used as a store of energy in
animals, and animals consume food to obtain energy and nutrients.
Nutrients
-Chemical that our body needs to keep in good health.
-Carbohydrates, fats and oils, proteins, vitamins, minerals, water and fibre
Proteins
○ Form muscles and bones.
○ It’s needed for growth and for repairing damage
● Carbohydrate
○ Stores of energy in animals
○ Must consume food to obtain
○ Plants make another carbohydrate which is cellulose which is used to
make cell walls and forms fibre.
■ starch, sucrose(used in food) and glucose(used in respiration)
● Fats and Oils
-Stores of energy in animals
-Must consume food to obtain
●
Liquid Fat
Solid Fat
-Produced by plants
-Evaporates from paper
-Produced by animals
-Doesn’t evaporate from paper
-Used as insulation beneath skin to keep body warm
-Oils are energy stores in plants
-Fats have more energy and are used up slower than carbohydrates. So they can use
this store energy if less food is found during winter. It also keeps them warm during
winter.
● Water
-70% of our body is made up of water
-Used to dissolve substances that our body needs.
-Used to cool down the body by sweat
-It’s found in all cells where chemical reaction takes place
-Because it’s the liquid that transports blood all over our body.
Mineral (Iron and Calcium)
-Our body needs 20 different minerals
-Calcium is needed to make strong bones and teeth
-Iron is needed by the red blood cell to transport oxygen around the body
-Lack of iron means less oxygen carried around the body which means that our body
will become weak and tired → anemia
-Anemia can be cured by increasing iron in our body
Vitamin
Effect on body
Good sources
A
Increases resistance to
disease and helps the
eye to see better in the
dark.
Milk, liver, cod-liver oil
C
Prevents scurvy
Papaya, guava, orange,
lemon
D
Prevents rickets
Egg yolk, butter,
cod-liver oil, sunlight
Scurvy - Bleeding occurs at the gums in the mouth, under the skin and joints - death
may occur due to massive bleeding
Rickets - Condition in which bones do not develop to their full strength and may bend
● Important Notes
-The have to consume food that has the nutrients
-Store of energy are energy that is stored in our body which can later be used to turn to
energy
8Bp.03 Discuss how human growth, development and health can be affected by
lifestyle, including diet and smoking.
Reference(s): EBOOK Grade 8,
Human growth & Development
● Smoking
○ Reduced appetite due to the nicotine
■ Prevents smokers from getting the nutrients they need
○ Reduced oxygen supply
■ Cigarette smoke contains carbon monoxide, which binds to
hemoglobin in red blood cells, reducing the amount of oxygen that
can be carried to tissues.
○ Nicotine is also an addictive substance which makes it difficult for
regular smokers to quit, causing a build up of harmful chemicals to the
human’s lungs and over body
● Diet
○ Malnutrition: diet provides too few or too many nutrients
Famine: lack of all foods
■ Crop failure
■ War (people have to move away from the crops)
Conclusion: Stunts growth and studies show children living in environments with lack of
food often grow smaller & less well developed
Health
● Smoking
○ Heart cancer
■ Due to the harmful chemicals
■ Inhale smoke (harmful chemicals) -> lungs and bloodstream ->
damage DNA -> damages cells (DNA controls how cells grow and
divide) -> cells grow and divide uncontrollably -> cells doesn’t die ->
tumor -> cancerous cells invade surrounding tissues -> immune
system failure -> cancer development
○ Breathing problems
■ Inhale -> damage to cilia -> swelling and narrowing of the bronchi
-> mucus overproduction -> destruction of air sacs -> reduced of
oxygen supply
○ Type 2 Diabetes
■ Chemicals (nicotine) and other toxins reduce the cells sensitivity to
insulin -> glucose cannot enter the cells efficiently -> elevated
blood sugar levels
○ Increased chance of strokes
■ Nicotine and carbon monoxide -> damage to blood vessels ->
increases the stickiness of platelets -> blood clots (block arteries in
the brain) -> raised blood pressure -> stroke (also caused by the
other effects from smoking I mentioned earlier)
● Diet
○ Deficiency Diseases
■ Lack of vitamin C: scurvy, bleeding gums, loosened teeth and
bleeding under your skin
■ Lack of vitamin D: rickets, weakened bones
■ Lack of Iodine: goiter, swelling in the neck, feeling of tiredness and
dizziness
■ Lack of iron: Anemia
● Iron is used to help transport red blood cells around the
body. Lack of iron -> lack of hemoglobin -> lack of oxygen ->
tired
■ Anemia: Caused by too little iron
■ Anorexia
● Can cause extreme weight loss
○
■
○ Cause to possible death
Obesity: Too many nutrients
● Extra strain on bones and joints
○ Damage to nerves and blood vessels in the feet (Only
treatable by amputation
● Can cause type 2 diabetes
○ The body no longer responds to insulin which helps
the body take extra sugar out to the liver
● Treatable through exercise
8Bp.04 Know that aerobic respiration occurs in the mitochondria of plant and animal
cells, and gives a controlled release of energy.
8Bp.05 Know and use the summary word equation for aerobic respiration (glucose +
oxygen -> carbon dioxide + water).
● Respiration
-Chemical process that releases energy
● Anaerobic respiration
-Does not require oxygen
● Aerobic respiration
-With air (Oxygen)
-Releases energy in cells (mitochondria) by breaking down food substances
-Word Equation = Oxygen + Glucose -> Carbon Dioxide + Water + ATP (Energy)
-Chemical Equation = O2 + C6H12O6 -> CO2 + H2O + ATP (Energy)
-Glucose is broken down by oxygen
-Happens in the mitochondria in the cells
● Photosynthesis
-Carbon Dioxide + Water -> glucose + Oxygen
-Oxygen from the air (stomata)
8Be.01 Identify different ecosystems on the Earth, recognizing the variety of habitats
that exist within an ecosystem.
8Be.02 Describe the impact of the bioaccumulation of toxic substances on an
ecosystem.
8Be.03 Describe how a new and/or invasive species can affect other organisms and an
ecosystem.
● Ecosystem
-Description of how a community of plants, animals, humans and microorganisms
interact with physical features such as the weather, rocks and soils.
-How living things interact with non-living things
● Bioaccumulation
-Living things can take in toxic substances (toxins) which are poisonous and harmful to
our body.
-Some toxins are broken down into harmless substances by chemical reaction and
released from the body, while others are released with solid waste(egestion). If not
removed, toxins accumulate in the body through bioaccumulation, damaging cellular
processes and potentially leading to death.
-Common toxins found in pesticides, which kill organisms like weeds and insects that
consume plants. If not used carefully, pesticides can spill into surrounding habitats,
affecting local plants and animals.
● Invasive species
-A species that enters an ecosystem where it doesn’t naturally belong to and it will
damage the ecosystem.