Science 9 Unit 6 - Cycles of Matter

Polarity of Water

Water is a polar molecule - one side is positive (hydrogen) one side is negative (oxygen). Creates strong intermolecular hydrogen bonds

Density of water

Water is denser in its liquid form than its solid form (a unique property because of the orientation of molecules - it expands)
Important because it allows living things to survive underneath the ice later (acts as insulation)

Specific Heat Capacity

The amount of energy required to raise the temperature of 1g of a substance by 1 degree C
Temp. of water rises and falls slower that most other liquids

Heat of Vaporization

Amount of heat required to change from liquid to gas.
Hydrogen bonds between water molecules require large amounts of heat to break, so water doesn’t evaporate easily

Solvent

Water dissolves a lot of solutions and can change their properties.

Dissociation

Atoms break off from molecules and form ions

Cohesion

Water molecules stick to each other (these hydrogen bonds create surface tension)

Adhesion

Water molecules stick to other substances

Condensation

Evaporated water (gas) turns into clouds (liquids)

Evaporation

Bodies of water (liquid) turn into gas

Precipitation

When clouds get heavy, the liquid falls because of gravity

Infiltration

Water from the surface of the planet sinks underground

Runoff

Water from the surface travels on the surface to a larger body of water

Transpiration

Plants sweating - evaporation of water from the stomata of leaves

Hydrologic Cycle

The Water Cycle

Toxic Pollution

Toxic pollutants (chemicals) in the water that cause death and birth defects if ingested.
Ex. Radioactive waste, pesticides, mercury, lead, gasoline, oil, paint, and battery acid

Sediment Pollution

Erosion of soil into waterways - sediments pile into reservoirs, rivers, harbors.
Caused by logging, mining, construction
Destroys fish + wildlife, cloud the water, and block sunlight from aquatic plants

Nutrient Pollution

The presence of excessive nutrients in the water
Caused by fertilizers, manure, untreated human waste, and some detergents
Promotes excessive algal growth (eutrophication) - algae decomposition consumes oxygen —> hypoxia —> kills aquatic organsims

Bacterial Pollution

Untreated human or animal waste released into water sources causing bacterial issues.
Caused by sources of fecal bacteria
Leads to outbreaks of cholera and dysentery

Biosphere

Biological/living part of Earth (plants, animals, bacteria, etc.)

Lithosphere

Geological part of Earth (rocks, fossil fuels, etc.)

Hydrosphere

Water-related parts of Earth (water cycle, oceans, etc.)

Atmosphere

Air-related parts of Earth (greenhouse gasses, ozone layer, etc.)

Photosynthesis (Carbon Cycle)

Plants take in carbon dioxide from the atmosphere

Respiration (Carbon Cycle)

Plants and animals release carbon dioxide back into the atmosphere as a byproduct of cellular respiration.

Burial

Dead matter become coal after being buried under pressure - carbon sink

Combustion

Burning of fossil fuels send carbon back into the atmosphere

Dissolution

Limestone rock releases carbon into the water through dissolution

Shell formation

Takes in carbon to form hard shells

Uplift

Limestone is lifted from underground to above ground

CO₂ Exchange

Carbon is absorbed and released by the ocean between the atmosphere continuously. Colder water = more carbon absorption.

Greenhouse Gasses

Carbon Dioxide (CO₂)
Methane (CH₄)
Water vapor (H₂O)
Nitrous Oxide (NO_x)
Fluorinated gases

Greenhouse Effect

Greenhouse Gasses in the atmosphere trap radiation and heat from the sun to reflect back to the Earth’s surface. This keeps Earth habitable, but too much cause global warming and climate change

Climate Change

The change in regional weather patterns

Global Warming

The increase in average temperature over the past decade.

Overshoot Day

The day people who have used their share of Earth’s resources for the year