Water

Percentages of water on earth, atmosphere and in human body

71% of earth’s surface is covered by water

4% of atmosphere is water vapor

65% weight of a human body is water

Why is water important

All living things require water therefor origin of life (including chemical reaction that sustain life) coincided with the presense of water

Start of life correlation with water

1. No sufficent atomosphere to block the suns radiation

2. water aborbs radiation which likly permitted organic molecules (and life) to form beneath the surface

3. Therefor some scientists believe that life began in the deep ocean near thermal vents

What is water

Polar molecules composed of 2 hydrogen and 1 oxygen atom covalentrly bonded together

Bonds around the water molecule

Negative charge around the oxygen

Positive charge around the hydrogens

define electronegativity

diffrent elements have stornger/weaker desire to hang onto molecules

5 properties of water

1. Cohesion

2. Adhesion

3. Surface tension

4. High specific heat of vaporization

5. Universal solvent

What properties of water allow for trees to get the water to the leaves

Cohesion and adhesion (also allow the flow of blood in your circulatory system)

Define cohesion

water sticks to itself

define adhesion

sticks to other surfaces

define surface tension

the result of all the surface water molecules orientated in the same direction, meaning they are tightly packed

WHat property of water contributes to surface tension

Cohesion

Define heat of vaporation and what it prevents

takes alot of energy to seperate many water molecules from each other

• prevents bodies of water from drying up in the summer

define specific heat and what it allows

High amount of energy is needed to raise the temperture of water by 1 degree celsius

• Allows for water to maintain temperature stability

Define universal solvent as a property of water and why it is possible

Water can dissolve many substances

• Since water has a positive charge around the hydrogens and a negative charge around oxygen

Define solute

Dissolved substance

Define solution

the combination of the solvent and the solute

define solvent

the dissolving agent (ex. Water)

define osomosis

can move in and out of cells

• Water will move into an area of lower solute concentration into an area with higher solute concentration

How does gatorate work

Intestinal cells absorb the electrolytes and water follows

Bonus property: Ice

Solid ice is unique in that it is less dense than liquid water

What is the main goal of nuclear power plants

To harness the energy of neutron radiaion to create high energy steam and generate electricity

What atom is used to create neutron radiation

Uranium - 235 (very unstable)

Nuclear fission

Release of neutrons causes other atoms and resultign atoms to decay which produces an insane amount of heat

process after heat is releasd

1. Heat is released from the fission of atoms is used to heat water in the reactor

2. Creates high pressure steam (water vapor)

3. Steam is used to turn a turbine, which produces electricity

4. Steam is released from massive cooling towers

Define thermal energy

The energy associated with the random movement of atoms and molecules

Define Heat

Thermal energy in transfer from a warmer to a cooler body of matter

define temperature

measures the intensity of heat

Define evaporative cooling

A process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest energy changing from the liquid to the gaseous state