Water, temperature and heat.

Question 1

List 6 charachteristics used to describe water?

Answer 1

odourless
tasteless
transparent
freezes at 0 degrees
boils at 100 degrees
necessary for life

Question 2

Explain the composition of water?

Answer 2

H2O 2 parts hydrogen 1 part water. water is rarely pure.

Question 3

Is water found pure anywhere in nature?

Answer 3

No because water has to go through many stages before the water becomes clear.

Question 4

How would you describe the weight of a volume of water?

Answer 4

water weighs 1.0 at 4 degrees

Question 5

Explain the water cycle?

Answer 5

1. The sun heats surface waters
2. This surface water evapourates into the air as ater vapour
3. At high level the water vapour cools too form clouds
4. The cooled water droplets, supported by rising convection currents, get larger and heavier until they fall back too the ground as rain.

Question 6

What causes water too be hard?

Answer 6

Hardness in water is caused by dissolved magnesium and calcium coming together.

Question 7

What is densilation?

Answer 7

Densilation is the removal of salt from sea water.

Question 8

How much water is the world made up of?

Answer 8

70% of the world is made up of water

Question 9

What percentage of a human is water?

Answer 9

The human body is made up of 60-70% water

Question 10

How much water do humans need a day?

Answer 10

2 litres per day to maintain good health

Question 11

Is water compressible?

Answer 11

Water is incompressible but fresh water does containmicroscopic air bubbles which can allow for very little compression to certain conditions.

Question 12

Is there air in fresh water?

Answer 12

yes there is air in fresh water

Question 13

How can this air be removed?

Answer 13

it can be removed by freezing the water

Question 14

Explain specific gravity in relation to water?

Answer 14

The weight of a given volume of any substance in comparison to the same volume of water at 4 degrees Celsius

Question 15

What is maximum density of water and what temp does it occur?

Answer 15

It is the temp at which water will no longer shrink. this occurs at 4 % Celsius

Question 16

What is the boiling point of water at sea level?

Answer 16

It boils at 100 degrees Celsius

Question 17

What would the boiling point of water be in a deep valley?

Answer 17

110 degrees Celsius

Question 18

what would the boiling point of water be on a mountain?

Answer 18

80 degrees Celsius

Question 19

What is the expansion rate of water as it turns too ice?

Answer 19

10% is the expansion rate when water turns too ice

Question 20

What is the expansion rate of cool water as it is heated too 80 degrees?

Answer 20

4% is the expansion rate when water is being heated

Question 21

When liquid, are water molecules far apart or nearer compared too ice?

Answer 21

the moloecules are nearer in comparison too ice

Question 22

what i the chemical symbol for lead?

Answer 22

pb is the chemical symbol for lead

Question 23

What is the chemical symbol for copper?

Answer 23

Cu is the chemical symbol for copper.

Question 24

What is the chemical symbol for steel?

Answer 24

Fe is the chemical symbol for steel.

Question 25

Explain what is meant by the term temperature?

Answer 25

Temperature is the measure of heat energy and dictates the rate of flow to a cooler object.

Question 26

What is 0 degrees kelvin on the Celsius scale?

Answer 26

-273 degrees Celsius

Question 27

Name 3 methods of heat transfer?

Answer 27

Conduction
Convection
Radiation

Question 28

Explain the term Conduction?

Answer 28

The transfer of heat thrugh a solid without the particles moving.

Question 29

Explain the term Convection.

Answer 29

The transfer of heat through the air caused when the molecules rise upwards after heating because they have become lighter

Question 30

Explain the term Radiation?

Answer 30

The transfer of heat to a solid object in straight lines without heating the air.