Ch. 2 - Cycles of Matter (Excluding AP Content) Flashcards
What elements make up 95% of all living things?
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur
What happens to these elements that make up most of living things?
They are cycled through the biosphere so they are available to living things.
What is the conversion of these elements of living things called?
Nutrient Cycling, and can be biotic or abiotic.
Water comprises how much of all plant and animal tissue? How much of the human body? How much of this water must humans replace daily?
More than 50% of all plant and animal tissue.
The human body is around 70%.
We lose and replace 3% of our water.
There is a limited amount of water in the biosphere. What happens to it so it doesn’t run out?
It has to be naturally recycled.
What percentage of water exists in liquid form?
More than 97%.
Water vapour is a greenhouse gas. What effect does it have on the planet?
Readily traps and transfers heat.
What happens to water as it is recycled through the atmosphere?
Purified and made available to organisms.
Water is also a product of cellular respiration. Water produced by cellular respiration is called what?
Metabolic water
What are the six main components of the water cycle? What’s the water cycle’s alternative name?
- Condensation
- Precipitation
- Infiltration
- Surface run-off
- Evaporation
- Transpiration
AKA. the Hydrologic Cycle.
In the water cycle, what is precipitation?
Any form of water that falls from the sky (rain, snow, hail, etc.)
In the water cycle, what is infiltration?
Surface water becomes groundwater by moving down through the soil.
In the water cycle, what is surface run-off?
When soil is infiltrated to full capacity, any excess water flows over the land.
In the water cycle, what is condensation?
Water vapour returns to liquid form, either by saturation (dew) or in clouds by accumulating in large droplets.
In the water cycle, what is evaporation?
Water ends up as a vapour in the atmosphere by evaporating from ponds, lakes, rivers, and oceans.
In the water cycle, what is transpiration?
The movement of water through a plant and its evaporation from leaves, stems, and flowers.
What is evapotranspiration?
Water vapour ends up in the atmosphere as a result of this: the combined evaporation and transpiration from a terrestrial area.
Where is the majority of evaporation from?
86% from the ocean.
What makes water so special?
Water has properties that make it an excellent carrier of dissolved material and other materials as well as an effective medium for transferring energy.
What are the four (five) unique properties of water?
- Water is a universal solvent
- Water has a relatively high melting and boiling point
- Water has special cohesive and adhesive properties
- Water has a high heat capacity
(Most dense at 4 degrees Celsius)
Why is water called the universal solvent?
As water moves from place to place or changes state, it carries a variety of substances with it. Some are beneficial, but others can be toxic.
Chemically, a water molecule is?
Two hydrogen atoms covalently bonded to an oxygen atom.
But, it is polar and forms hydrogen bonds between the one slightly negative oxygen molecule and the slightly positive hydrogen molecules of nearby other molecules.
What type of compounds does the structure and polarity of water allow it to do?
Dissolve a wide range of substances from molecular compounds such as CO2 to ionic compounds like NaCl -> Na+, Cl-
Are individual hydrogen bonds strong?
No, they are relatively weak and in liquid water they break and reform constantly.
Despite the weakness of individual hydrogen bonds, why does water still have such a high melting and boiling point?
Many hydrogen bonds are very strong. These bonds must be broken in order for water to change from liquid to gas. Thus, lots of energy is required to boil water.
What property of ice (melting point) is influenced by hydrogen bonds?
It has a relatively high melting point.
Unlike most substances, water in its solid state has what property?
Solid water (ice) is less dense than water in its liquid state.
The hydrogen bonds in ice form what?
They hold water molecules in an open crystal structure.
Due to the open crystal structure of water, what happens to water as it freezes?
It expands.
As ice melts, what happens to the crystal structure?
It collapses and density increases.
At what temperature does water reach its highest density?
4 degrees Celsius. After that density decreases because of thermal expansion.
How do nutrients cycle in lakes in the spring?
- Water becomes more dense as it warms until 4 degrees.
- The denser water sinks
- This leaves colder water at the surface to be warmed by the Sun
- The colder water subsequently sinks
(repeat)
How do nutrients cycle in lakes in the fall?
- Water becomes cooler towards 4 degrees Celsius
- The cooler water becomes denser and sinks
- This leaves warmer water on top
- The warmer water cools and sinks until it reaches maximum density at 4 degrees Celsius.
As water sinks and rises, what happens to nutrients and oxygen?
Nutrients and oxygen are cycled with it.
How does water unlock nutrients? (Define percolation)
Water percolates into spaces in rocks and expands when it freezes, weathering rocks to create sand and soil and nutrients in the process.
“Break up”
What is the role of ice floating on top of the lake?
They insulate the water and keep it from freezing to the bottom.
The bottom is often warmer because of radiating ground heat.
What is cohesion?
Attraction of water molecules to each other, is responsible for surface tension.
Surface tension helps organic debris on top of the water where they provide nutrients for aquatic organisms.
Ex: For water striders
What is adhesion?
Attraction of water molecules to other substances.
Water molecules are attracted to the inner surface of a tree’s xylem tissue, providing an upward force to help move water from the roots to the leaves.
What happens as a result of the hydrogen bonding in water to its heat capacity?
This results in a high heat capacity, meaning that it requires large amounts of energy to cause small temperature changes
Water heats up more slowly and holds heat longer than almost any other liquid.
How does water’s high heat capacity affect living organisms like us?
Because living organisms have a large concentration of water in their tissues, water’s high heat capacity allows them to maintain a fairly consistent internal temperature.
What does water’s high heat capacity have on climate?
Bodies of water have a moderating effect on air temperature over nearby land.
How is heat transferred near the equator?
Near the equator, large amounts of heat energy heat the ground, causing evaporation. Evaporated water rises and moves towards the poles, distributing its heat as it cools. Process distributes heat away from the equator.
What are ocean currents and what do they do?
These transfer warm water to cooler regions. The warm water heats air and moderates temperatures over nearby land. Have a large impact on climate.
What were Canada’s two largest water-related natural disasters?
Droughts in the 1930s and the 1980s.
If global temperatures rise, what happens to water?
Rate of evaporation increases.
Plants closes stomata, less CO2 taken, less photosynthesis, more CO2.
What causes our increased demand for water? What does it cause?
The increased demand for water caused by population and industrial growth would put Alberta’s rich supplies of fresh water in danger.
