<td>A measure of how much mass is contained in a given unit volume of a substance; calculated by dividing the mass of a sample of its volume <b>(mass/volume)</b></td>
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<td>Element</td>
<td>Element An element is made up of the same atoms throughout, and cannot be broken down further</td>
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<td>Metal</td>
<td>a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity</td>
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<td>Pure substance</td>
<td>A substance that is made up of only one type of particle</td>
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<td>Atom</td>
<td>The smallest unit of matter found in substances</td>
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<td>Solution</td>
<td>A uniform mixture of 2 or more substances</td>
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<td>Colloid</td>
<td>is substance with small particles suspended in it, unable to be separated by gravity</td>
<td>A physical property that is unique to a substance and can be used to identify the substance</td>
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<td>Periodic Table</td>
<td>a table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns.</td>
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<td>Compound</td>
<td>Compounds are chemically joined atoms of different elements</td>
|Brittleness|Breakability or flexibility<br> Glass would be considered as brittle whereas slime/clay are flexible|
|Viscosity|The ability of a liquid or gas to resist flow or not pour readily through<br> Refer to as more or less viscous|Molasses is more viscous, water is less (gases tend to get"thicker as heated; liquids get runnier)|
|Hardness|The relative ability to scratch or be scratched by another substance<br> Referred to as high or low level of hardness| Can use a scale (1 is wax, 10 is diamond)|
|Malleability|the ability of a substance ```to be hammered``` into a thinner sheet or molded|Silver is malleable<br> Play dough/pizza dough is less<br> glass is not malleable|
|Ductility|the ability of a substance to be pulled into a finer strand|Pieces of copper can be drawn into thin wires, ductile|
|Electrical Conductivity|The ability of a substance to allow electric current to pass through it<br> Refer to as high and low conductivity|Copper wires have high conductivity<br> Plastic has no conductivity|
|Form: Crystalline Solid|Have their particles arranged in an orderly geometric pattern|Salt and Diamonods|
|Form: Amorphous Solid|Have their particles randomly distributed without any long-range-pattern|Plastic, Glass, Charcoal|
- A characteristic (property) of a substance that describes its ability to undergo ```changes to its composition to produce one of more new substances. AKA BEHAVIOUR. Everything has one!```
- ```Cannot be determined by physical properties```
- Every species interacts with other species and with its environment in a unique way. This is its role in an ecosystem (e.g. what it eats, what eats it, how it behaves, etc.)
- Energy flow through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various hetrotrophs (consumers).
- Food are a series of steps in which organisms transfers energy by eating or eaten (pg. 43).
- Food webs show the complex interactions within an ecosystem (pg. 44).
- Each step in a food chain or web is called a `trophic` level. Producers make up the first step, consumers make up the higher levels. E.g. first trophic level are producers, second trophic level are primary consumers, etc.
## ECOLOGICAL PYRAMIDS
- Food chains and food webs do not give any information about the numbers of organisms involved.
- This information can be shown through ecological pyramids.
- An ecological pyramid is a diagram that shows the amount of energy or matter contained within each trophic level in a food web or food chain.
|Pyramid of Biomass|Show the **total** amout of `living tissue` available at each `trophic` level. This shows the amount of tissue available for the next `trophic` level. <br><br> Biomass is preferred to the use of numbers of organisms because individual organisms can vary in size. It is the `total mass`**(not the size)** that is important. Sometimes it’s inverted. <br><br> Pyramid of biomass records the total dry organic matter of organisms at each trophic level in a given area of an ecosystem.|<imgsrc="http://earth.rice.edu/mtpe/bio/biosphere/topics/energy/biomass_pyramid.gif"width="800">
|Numbers Pyramids|Shows the number of organisms at each trophic level per unit area of an ecosystem. <br><br> Because each trophic level harvests only about `one tenth` of the energy from the level below, it can support only about one `10th` the amount of living tissue. <br><br>**`Can be inverted`**: 1 large tree supports thousands of organisms living on it <br><br> Pyramid of numbers displays the number of individuals|<imgsrc="https://d321jvp1es5c6w.cloudfront.net/sites/default/files/imce-user-gen/pyramidnumbers2.png"width="400">|
|Energy Pyramid|Shows the amount of energy input to each trophic level in a given area of an ecosystem over an extended period.<br><br>**CANNOT** be inverted, due to energy transfers<br><br>**Only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level**|<imgsrc="https://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Ecological_Pyramid.svg/1200px-Ecological_Pyramid.svg.png"width="500">|
**NOTE FOR ENERGY PYRAMIDS**: In nature, ecological
efficiency varies from `5%` to `20%` energy available between successive trophic levels (`95%` to `80%` loss). About 10% efficiency is a general rule. `Rule of 10’s` at each level.
-`Nitrogen Fixation`: The process that causes the strong two-atom nitrogen molecules found in the atmopshere to break apart so they can combine with other atoms.
-`Nitrogen gets fixed`: Whenit is combined with oxygen or hydrogen.
- An essential component of DNA, RNA, and protenis - the building blocks of life.
- Atmopspheric nitrogen = N<sub>2</sub>
- Most living organisms are `unable` to use this form of nitrogen
- Therefore, must be **converted** to a usable form!
- Highly specialized bacteria live in the soil and have the ability to combine atmospheric nitrogen with hydrogen to make ammonium(NH<sub>4</sub><sup>+</sup>).
- Nitrogen changes into ammonium.
2. Symbiotic Relationship Bacteria
- Bacteria live in the roots of legume family plants and provide the plants with ammonium(NH<sub>4</sub><sup>+</sup>) in exchange for the plant's carbon and a protected biome.
-`Nitrites` are absorbed by plant roots and converted to plant protein.
-`Nitrates`**can be absorbed by other plants** to continue the cycle.
-`Denitrifying bacteria` convert soil nitrates into N<sub>2</sub> gas
- This is a `loss` of N<sub>2</sub> from the cycle
### Human Impacts
- Nitrates also `enters` the cycle **through the addition of nitrogen rich fertilizers to the soil**– made industrially from nitrogen gas (Eutrophication – pg. 60)
- Nutrients are then taken up by other plants and used to make new organic material.
- This material is passed on down the food chains and is reused by all the chain members.
- When death occurs for these members, the nutrients are again returned to the abiotic environment and the cycling of nutrients continues in this circular way.
- This ensures that there is no real longterm drain on the Earth’s nutrients, despite millions of years of plant and animal activity.
### Summary Of Nutrient Recycling
- The way in which elements are continuously being broken down and/or exchanged for reuse
- Occurs between the living and non-living components of an ecosystem.
