Water, temperature and heat. Flashcards
List 6 charachteristics used to describe water?
odourless tasteless transparent freezes at 0 degrees boils at 100 degrees necessary for life
Explain the composition of water?
H2O 2 parts hydrogen 1 part water. water is rarely pure.
Is water found pure anywhere in nature?
No because water has to go through many stages before the water becomes clear.
How would you describe the weight of a volume of water?
water weighs 1.0 at 4 degrees
Explain the water cycle?
- The sun heats surface waters
- This surface water evapourates into the air as ater vapour
- At high level the water vapour cools too form clouds
- The cooled water droplets, supported by rising convection currents, get larger and heavier until they fall back too the ground as rain.
What causes water too be hard?
Hardness in water is caused by dissolved magnesium and calcium coming together.
What is densilation?
Densilation is the removal of salt from sea water.
How much water is the world made up of?
70% of the world is made up of water
What percentage of a human is water?
The human body is made up of 60-70% water
How much water do humans need a day?
2 litres per day to maintain good health
Is water compressible?
Water is incompressible but fresh water does containmicroscopic air bubbles which can allow for very little compression to certain conditions.
Is there air in fresh water?
yes there is air in fresh water
How can this air be removed?
it can be removed by freezing the water
Explain specific gravity in relation to water?
The weight of a given volume of any substance in comparison to the same volume of water at 4 degrees Celsius
What is maximum density of water and what temp does it occur?
It is the temp at which water will no longer shrink. this occurs at 4 % Celsius
What is the boiling point of water at sea level?
It boils at 100 degrees Celsius
What would the boiling point of water be in a deep valley?
110 degrees Celsius
what would the boiling point of water be on a mountain?
80 degrees Celsius
What is the expansion rate of water as it turns too ice?
10% is the expansion rate when water turns too ice
What is the expansion rate of cool water as it is heated too 80 degrees?
4% is the expansion rate when water is being heated
When liquid, are water molecules far apart or nearer compared too ice?
the moloecules are nearer in comparison too ice
what i the chemical symbol for lead?
pb is the chemical symbol for lead
What is the chemical symbol for copper?
Cu is the chemical symbol for copper.
What is the chemical symbol for steel?
Fe is the chemical symbol for steel.
Explain what is meant by the term temperature?
Temperature is the measure of heat energy and dictates the rate of flow to a cooler object.
What is 0 degrees kelvin on the Celsius scale?
-273 degrees Celsius
Name 3 methods of heat transfer?
Conduction
Convection
Radiation
Explain the term Conduction?
The transfer of heat thrugh a solid without the particles moving.
Explain the term Convection.
The transfer of heat through the air caused when the molecules rise upwards after heating because they have become lighter
Explain the term Radiation?
The transfer of heat to a solid object in straight lines without heating the air.
