1. Unit II Properties of Water

2. Unit II Properties of Water
Three physical states of Water
Solid
Liquid
Gas or Vapor

3. Unit II Properties of Water
When water freezes it expands to form ice

4. Unit II Properties of Water
Water as a liquid
Rivers
Streams
Lakes
Ponds
Aquifers

5. Unit II Properties of Water
Water moves as a gas or vapor through the atmosphere.
Mechanisms or ways water is transported as a gas are:
Transpiration (from plants)
Evaporation (sun energy)
Clouds (condensation)

6. Unit II Properties of Water

7. Unit II Properties of Water
Cohesion causes water molecules to be drawn together, which is why drops of water form beads on a smooth surface. Cohesion also produces surface tension.”

8. Unit II Properties of Water
Water striders are able to walk on top of water due to a combination of several factors. Water striders use the high surface tension of water and long, hydrophobic legs to help them stay above water. Water molecules are polar and this causes them to attract to each other. The attractive nature results in the formation of a film-like layer at the top of water. This top layer has gravity acting downward in addition to the water molecules below pulling down the upper molecules. This combination creates surface tension

9. Unit II Properties of Water
Adhesion when water sticks to another surface
Fun Fact
there are about 5 sextillion atoms in a drop of water.

10. Unit II Properties of Water
Water has the ability to moderate temperature, that’s why water has the highest specific heat of any liquid. Pictured is an example of geothermal energy.

11. Unit II Properties of Water
In nature water is the Universal Solvent (The brown color is due to tannic acids dissolved in water)

12. Unit II Properties of Water
Water is a polar molecule, and polarity occurs when the electrons in molecules are not spread evenly. This causes one end of the molecule to be negative, while the other is positive.

13. Water Cycle

14. Nitrogen Cycle
The nitrogen cycle describes how nitrogen moves between plants, animals, bacteria, the atmosphere (the air), and soil in the ground. Nitrogen is an important element to all life on Earth.

15. Nitrogen Cycle
Different Nitrogen States For Nitrogen to be used by different life forms on Earth, it must change into different states. Nitrogen in the atmosphere, or air, is N2. Other important states of nitrogen include Nitrates (N03), Nitrites (NO2), and Ammonium (NH4).

16. The most important part of the cycle is bacteria
The most important part of the cycle is bacteria. Bacteria help the nitrogen change between states so it can be used. When nitrogen is absorbed by the soil, different bacteria help it to change states so it can be absorbed by plants. Animals then get their nitrogen from the plants.

17. Processes in the Nitrogen Cycle Fixation
Nitrogen Cycle Fixation - Fixation is the first step in the process of making nitrogen usable by plants. Here bacteria change nitrogen into ammonium.
Nitrification - This is the process by which ammonium gets changed into nitrates by bacteria. Nitrates are what the plants can then absorb.
Assimilation - This is how plants get nitrogen. They absorb nitrates from the soil into their roots. Then the nitrogen gets used in amino acids, nucleic acids, and chlorophyll.
Ammonification - This is part of the decaying process. When a plant or animal dies, decomposers like fungi and bacteria turn the nitrogen back into ammonium so it can reenter the nitrogen cycle.
Denitrification - Extra nitrogen in the soil gets put back out into the air. There are special bacteria that perform this task as well.

18. Why is nitrogen important to life?
Plants and animals could not live without nitrogen. It is an important part of many cells and processes such as amino acids, proteins, and even our DNA. It is also needed to make chlorophyll in plants, which plants use in photosynthesis to make their food and energy.
How have humans altered the nitrogen cycle? Unfortunately, human activity has altered the cycle. We do this by adding nitrogen into the soil with fertilizer as well as other activities that put more nitrous oxide gas into the atmosphere. This adds in more nitrogen than is needed by normal cycle and upsets the cycle's balance.

20. Aquaponics

21. Aquaponics
Use the internet to investigate Aquaponics then complete the work sheets about water