Properties of Water

Oceans 11G.Burgess

2009.

No two oceans are alike

• Ocean water is different depending on the location, season and time of day.

• Our oceans regulate our climate

Importance

• They are our most important resource• Also acts as a sink (storage) for componds

such as CO2, salts, minerals (ie calcium, magnesium, iron)

• Supports all life on Earth• Plankton is a major producer of oxygen

Chemistry of water

• Chemical formula: H2O• Polar molecule: H+, O-

• Polarity comes from the positioning of the electrons that make-up each atom

Surface tension• the ability of the surface molecules to stay

together.• Water molecules are attracted to each other

(they try to hold onto each other)• The surface tension is strong enough for some

organisms to walk on the top or bottom of the surface.

• Surface molecules are pulled toward the center

• Reason for forming rounded water drop

Heat Capacity

• Water has one of the highest abilities to hold heat

• This means that it can be heated without changing temperature

• It also means that it can store heat very well

States of water

• Only substance to be found on Earth in all three states – solid, liquid, gas

• 0°C: freezing point (freeze, melt)• 100°C: boiling point

(vaporization, condensation)• Water can , under low pressure, change

from solid to gas - Sublimation