Natural Science 1
Answer Key
/page 5/
The Earth in the Universe
The Universe and the Solar System
Activity 1
2 c, 3 d, 4 e, 5 a
Activity 2
1 about five billion years
2 the Sun, planets, dwarf planets, moons, asteroids, comets and other smaller bodies.
3energy in the form of light and heat
Activity 3
1 eight planets, and five dwarf planets
2
inner planets: Mercury, Venus, Earth, Mars
outer planets: Jupiter, Saturn, Uranus, Neptune
3
rocky planets: Mercury, Venus, Earth, Mars
gaseousplanets: Jupiter, Saturn, Uranus, Neptune
4 a dwarf planet
Activity 4
1 theAsteroid Belt
2 the Kuiper Belt
/page 7/
Planet Earth
Activity 1
1 the geosphere
2 the part of the Earth made up of water
3 allthe living things on Earth
Activity 2
1 an atmosphere which contains oxygen
2 an average temperature of 15ºC
3 water (in solid, liquid and gaseous states)
4 its own magnetic field which helps protect it from dangerous solar radiation.
Activity 3
1 Yes. Saturn has 60. Jupiter has 63.
2 There is no free oxygen in the atmosphere of Venus.
Activity 4
1 rotation
2 an axis
3 days and nights
4 revolution
5 the Sun
6 seasons
Activity 5
equinox: When the Earth’s axis is not tilted in relation to the Sun (so the Sun appears to be directly overhead at the Equator).
solstice: When the Earth’s axis is tilted at the greatest angle in relation to the Sun.
Activity 6
1 approximately one month (27.32 days)
2 approximately one month (27.32 days)
3anew Moon
b first quarter or crescent Moon
c full Moon
d last quarter or crescent Moon
/page 9/
Matter.Properties
Activity 1
1 Matter: Everything that has mass and occupies a space.
2 Quantity:A thingwhich can be measured, e.g. massand volume.
Activity 2
1 20,000 g
2 scales or electronic balance
3 2 dm3
4 measuring cylinder
Activity 3
1 density
2a2,700 kg/m3
b7.855 g/cm3
c13.6 g/cm3
3 8 ml / 8 cm3
/page 11/
Matter.States
Activity 1
1 shape, volume, close
2 liquid, freedom
3 containers
4 constant
5 gaseous
Activity 2
1 melting
2 solidification / fusion
3 vaporisation / evaporation
4 condensation
5 inverse sublimation / deposition
6 sublimation
Activity 3
1 False. The change from the solid state to the liquid state is called melting.
2 False. In a solid, the links between particles are strong.
3 True.
4 False. In the gaseous state, matter does not have a constant shape or volume.
Activity 4
Suggested answers:
1 The level of water in a fish tank falls over time as the water evaporates.
2 When water turns to ice in the freezer.
3 When ice cream becomes liquid if left out of the freezer.
4 When water droplets appear on a mirror in the bathroom after a hot shower.
/page13/
Matter.Classification
Activity 1
1 A pure substance has a definite chemical composition
2 An element is made up of a single type of atom.
3 A compound is made up of several different atoms.
4 A mixture is a combination of two or more substances which have different specific properties.
5 In a homogenous mixture you cannot see the different components. In a heterogeneous mixture you can see the different components.
Activity 2
homogenous mixtures: air, oil, milk, water and alcohol, water and sugar
heterogeneous mixtures: granite, sparkling water, water and oil, water and ice
Activity 3
1 c, 2 b, 3 d, 4 a
Activity 4
1 distillation
2 evaporation
3 decantation
4 sieving
The Structure of the Earth
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The atmosphere.Composition and characteristics
Activity 1
1 Theatmosphere is a gaseous layer which surrounds the planet Earth.
2 aOxygen (O2,) It is vital to life on Earth.
b other gases: Ozone (O3)is found in the stratosphere. The ozone layer
blocks ultraviolet rays. Carbon dioxide (CO2) is produced by animals through respiration, and is used by plants and algae in photosynthesis. It is an important greenhouse gas. Argon (Ar) has been present in the Earth’s atmosphere since the origin of the atmosphere.
c Nitrogen, (N2), is the most abundant gas in the atmosphere. It is very stable.
Activity 2
Students’ own answers.
Activity 3
1 ionosphere
2 mesosphere
3 stratosphere
4 troposphere
5 mesopause
6 stratopause
7 tropopause
8 +1,000ºC
9 -90ºC
10 0ºC
11 -50ºC
12 +15ºC
The Northern Lights are formed in the ionosphere.
/page17
The atmosphere.Atmospheric phenomena
Activity 1
1 Weather is the state of the atmosphere at a precise moment in a specific place.
2 Meteorologists study weather and atmospheric conditions.
3 Climate is the average weather of a certain place over a long period of time.
Activity 2
1 An anemometer measures wind speed.
2 Arain gauge measures volume of rain water.
3 Athermometer measures temperature.
4 Abarometer measures atmospheric pressure.
5 Aweather vane measures wind direction.
Activity 3
Students’ own answers.
Activity 4
1 A weather map showing atmospheric pressure.
2
3 a D, depression
4 b A, anti-cyclone
/page 19/
Water.The hydrosphere
Activity 1
1 polar ice caps, snow and ice, glaciers, icebergs
2 rivers and streams, lakes, groundwater, seas and oceans
3 water vapour, clouds
Activity 2
1 97%
2 on the continents (inland water)
3 inland water
Activity 3
1 fresh water
Activity 4
1 H2O
2 No. Because the density of ice is lower than that of water, so the ice floats.
3 At 0ºC.
4 At 100ºC
Activity 5
1 good regulator of climate
2 good solvent
3 agent of transport
4 agent of erosion
/page 21/
Water.The water cycle
Activity 1
1 evaporation
2 condensation
3 evapotranspiration
4 precipitation (rain)
5 precipitation (snow)
6 snowmelt
7 infiltration
8 groundwater
Activity 2
1 snow/hailstones
2 snowmelt
3 runoff
4 groundwater
5 the Sun
6 evapotranspiration
Activity 3
1 d, 2 c, 3 a, 4 b
Activity 4
Suggested answers:
1 Because it can contain substances and organisms which are harmful to human health, or cause disease.
2 chlorine (Cl)
3 Because it is an increasingly limited resource.
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Minerals
Activity 1
1 The Earth's crust.
2 are inorganic.
3 solid
4 definite chemical composition.
5 arranged in a very regular order.
Activity 2
hardness, colour, streak, cleavage, crystal structure
Activity 3
2 gypsum
3 calcite
4 fluorite
5 apatite
6 feldspar
7 quartz
8 topaz
9 corundum
Activity 4
Students’ own answers.
Activity 5
Students’ own answers.
/page 25/
The geosphere and rocks
Activity 1
1 the core (inner and outer),the mantle, the crust
2 the crust, the mantle
3 mainly nickel and iron
Activity 2
1 igneous rocks
2 plutonic rocks
3 volcanic rocks
4 sedimentary rocks
5 metamorphic rocks
Activity 3
1 b, 2 c, 3 a
Activity 4
1 wind, ice and water
2 at the Earth's surface
3 deep inside the Earth
4 deep inside the Earth
Activity 5
1 erosion
2 transport
3 sedimentation
4 compression
5 cementation
6 sedimentary rock
Life on Earth
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Living things.Cells
Activity 1
1 organisms which are born, grow, reproduce and die.
2 carbon, hydrogen, oxygen and nitrogen.
3 and become organised to form large complex structures which form cells.
4 inorganic and organic.
5 vitamins.
Activity 2
A
1 mitochondrion
2 nucleus
3 cell wall
4 plasma membrane
5 vacuole
6 chloroplast
7 cytoplasm
B
1 vacuole
2 nucleus
3 mitochondrion
4 cytoplasm
5 plasma membrane
Activity 3
1 multi-celled organisms
2 the cell membrane, the cytoplasm and the genetic material (DNA)
3 In a eukaryotic cell the genetic material is found inside the nucleus, separated from the cytoplasm by a membrane.
4 Plant cells are generally many-sided cells and have a cell wall. Some plant cells also contain chloroplasts where photosynthesis happens. Animal cells can take different forms, according to their function and do not have chloroplasts or cell walls.
Activity 4
Students’ own answers.
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Living things. Vital functions. The five kingdoms of living things
Activity 1
1 c, 2 a, 3 b
Activity 2
1 autotrophicnutrition, heterotrophicnutrition
2 Autotrophicnutrition is a process in which organisms create their own nutrients from sunlight or from CO2, and also from mineral substances and water they take from the earth
3 algae, plants
4 fungi,animals
5 Asexual reproduction: only one individual is needed for the reproductive process. Sexual reproduction: two sexual cells (gametes) of different sexes are required for reproduction.
6 adaptation
Activity 3
1 Monera, Protista, Fungi, Plants, Animals
2 Monera, bacteria
3 Protista, Fungi, Plants, Animals
4 Plants are eukaryotic, multi-celled and autotrophic organisms. The cells join together and form tissues. They are unable to move from place to place independently.
5 Fungi are heterotrophic, not autotrophic. They do not have tissues.
6 Animals are heterotrophic, not autotrophic. They are also able to move from place to place independently.
Activity 4
Living things Kingdom Organism Type of nutrition
lion, wolf / animal / eukaryotic multi-celled / heterotrophicbacteria / monera / prokaryotic single-celled / autotrophic or heterotrophic
mushrooms / fungi / eukaryotic single-celled or multi-celled / heterotrophic
pine trees, roses / plant / eukaryotic multi-celled / autotrophic
algae / protista / eukaryotic single-celled or multi-celled / autotrophic
/page 31/
Practical work: the microscope
Experiment 1
Students’ own answers.
Experiment 2
Students’ own answers.
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Natural Science 1 – Answer Key