MODULE 3
2
WORKSHEET
WATER ON EARTH
Syllabus reference 8.4.1
1
Classify each of the following statements as true or false. For the statements that are false rewrite
them so they are true.
a
Most of the water on Earth is found in the oceans.
TRUE
b
The atmosphere does not contain any water because it is made up of gases.
FALSE
c
The atmosphere CONTAINS WATER VAPOUR AND TINY LIQUID DROPLETS.
Water is the only substance which exists naturally in three states simultaneously.
TRUE
d
Water contracts (gets smaller) when it freezes.
FALSE
e
More things can be dissolved in oil than in water.
FALSE
f
Water EXPANDS when it freezes.
More things can be dissolved in WATER than in OIL.
Condensation is water coming out of the air.
TRUE
g
A solution is made up of a solute and a solvent.
TRUE
h
The substance which dissolves is called the solvent.
FALSE
i
The substance which dissolves is called the SOLUTE.
All living things need water to survive.
TRUE
j
Water bodies show greater temperature fluctuations than land or air.
FALSE
Water bodies show SMALLER temperature fluctuations than land or air.
Copyright © 2008 McGraw-Hill Australia
CONQUERINGCHEMISTRY PRELIM
MODULE 3 WS 2
2
Complete the following table comparing the state, percentage and distribution of water on Earth.
STATE (SOLID, LQUID, GAS)
ZONE OF THE EARTH
Atmosphere
Vapour or tiny liquid droplets
(in clouds)
0.5 to 5%
Hydrosphere
Liquid (with other substances
dissolved in it) and solids (in
polar icecaps)
>95% in oceans
Also in polar icecaps, lakes
and rivers
<10%
Lithosphere
Biosphere (living matter)
3
% OF THE ZONE
Liquid as ground water
Liquid (with other substances
dissolved in it)
Between 60 and 90% overall,
but to 50 to 75% in humans
(decreases with age); up to
95% in jellyfish
List three processes in which water plays a major role in living things.
A raw material (used in the chemical reactions that constitute life).
A solvent in which life processes occur.
A transport medium for bringing nutrients to cells and removing waste products.
A thermal regulator by smoothing out sudden and large temperature variations.
4
Give one advantage of water as a habitat compared with land.
Water bodies have the advantage of less fluctuation in temperature than land and air masses.
5
What role does water play in changing the surface of the Earth?
Water is the main weathering and eroding agent of the Earth.
Rivers and rain wash loose material to lower altitudes and eventually to the sea.
Glaciers cut a swathe from mountain tops through weaker rocks to the oceans.
Freeze–thaw mechanism sees liquid water seep into small cracks in rocks, freeze and expand thus
widening the crack until large fragments of rock break away.
6
Apart from drinking and washing, list four ways in which humans use water.
• Food preparation
• Irrigating crops and watering livestock
• In industry as solvent, cleaning agent,
waste disposal and settling dust
• Working fluid in many industries
• Mode of transport
• Hydro-electricity
• Recreational purposes
Copyright © 2008 McGraw-Hill Australia
CONQUERINGCHEMISTRY PRELIM
MODULE 3 WS 2