53

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

By the end of this unit you should be able to:

Compare different rocks and group them

Realize we rocks based on their properties

Know that:

- The rock is the solid part of the Earth's crust.

- Different rocks show different properties.

- The causes of weathering.Soils are formed from rocks.

- Types, Characteristics and properties of different soil.

Unit 5E.1: Rocks and How We Use Them

Looking at rocks

Using rocks

Weathering

Soil

Science skills:

Observing

Classifying

54

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Looking at Rocks

What do we walk on? Live in? Climb sometimes?

Sit on sometimes?

Rocks!

Looking at Rocks

Are all rocks the same? Are the rocks shown here the same?

Can you describe how they are different?

Classifying rocks:

Getting ready:

In this activity you will observe and classify Rocks according to

their properties.

5.11.1

55

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Materials you need:

- 5 different rock samples

labelled 1 to 5

- Hand lens

- Dropper, Vinegar

- Safety goggles

- Paper plate

- Paper towels, Beaker

- Water, Glass plate

Procedure:

1. Make a chart like the one

shown at the end.

2. What colour or colours in

each rock?

3. Can you see any grains?

Are the grains very small or large? Record your

observation under texture in your chart.

56

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

4. Rub each rock against other rocks

and find out whether it easily marks

other rocks or a concrete floor.

The softer rocks leave marks on

the harder ones! Write if it leaves

a mark under ‘rubbing’

5. Using a hand lens, observe how many

pores (small empty holes) you can

see in the rock. Test by putting a

few drops of water on it. If it

allows water to go through it is

porous. This is what we call

porosity.

6. Caution: wear your safety goggles.

Use the dropper to add a few drops

of vinegar on each rock.

57

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Record your observation:

Rock

sample

1 2 3 4 5

Colour

Texture

Rubbing

Porosity

Bubbles

when

vinegar

added

58

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Where are rocks found? Look at the following pictures and

discuss where the rocks can be found? Also think about why

can we see some rocks and not others:

59

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Rocks lie beneath all surfaces of the Earth:

Why do you think these rocks are so smooth?

60

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Using Rocks

Uses of rocks depend on their properties.

Try and complete as much of the table below as possible, your

teacher will help once you have tried yourself.

Here is a clue to start you off...

5.11.2

How is this rock

being used? Discuss

with your partner?

How did they make?

61

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Uses of rocks I

have seen – draw a

picture if you like!

What is the name

of the Rock used

Why is this rock

used?

62

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Rocks are traditionally used as building materials. Look at this

house! It is made from natural rocks! People used to make such

homes before. We now have the machinery to use rocks as we

need –make cement, bricks etc

Look at the house below quite clever what do you think?

Now, we use different rocks for different jobs depending on

their properties..

63

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Examples:

Limestone and sandstone are used as building blocks

Slate is used for roofing tiles.

Granite and marble are much harder than limestone and

sandstone. They are used for statues and headstones.

WRITE THE TYPE OF ROCK UNDERNEATH!

64

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Research..

Find out about the following famous places, make posters and

try and find different pictures to add to your poster, include

information: How the different rocks are used? When it was

built? What types of rocks etc.

Clues: Egypt, (Aztec) Mexico, Yemen, Petra (Jordan)

65

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Clay is used to make an important building material caked

Cement.

To learn more about the rocks and their uses, Study this

table:

Name of rock

Properties

Uses

Limestone

Hard and

coloured

Building blocks

Quartz

Attractive

colours

Jewellery

66

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Slate

Water

proof

Roofs and buildings

Granite

Hard

Steps, floors

Marble

Attractive

and can be

polished

Steps floors

Chalk

Breaks

easily

Writing

Soapstone

Soft and

may feel

soapy when

touched

Inlaid designs,

statue, kitchen and

for traditional

carvings.

67

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Key words:

Stone Age Lime stone Quartz

Slate Granite Marble

Chalk Soapstone

Do you know?

The most rocks in Qatar are sedimentary, so they have

many pores (high porosity) which make them good containers

for petrol and natural gas.

Key Idea:

Rocks have different uses depending on their properties

68

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Key questions:

Fill these spaces using the following words:

a) Steps

b) Roofs

c) Writing

d) Statues

Explain the following observations:

a. Limestone and sandstone are good building

materials because...

__________________________________________

b. Slate is good for roofing because..

__________________________________________

c. Granite chips are good for road making because..

d. Stone carvers like using soapstone for their work.

__________________________________________

__________________________________________

69

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Soil: Where does soil come from?

Let’s first ask where did the sand come from?

This is in Zikreet! The picture gives you a clue!

Weathering

The surface of the Earth is always changing – like in Zikreet.

This may come as a surprise, as the rocks and hills look the

same for years! This is because the process of changes happens

very slowly. The rocks slowly break into smaller pieces – we call

it weathering.

Weathering: is the breaking down of rocks into smaller

and smaller pieces.

5.11.3

You can make your own sand! Place a piece of white paper and rub the rock with your fingers!

70

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Causes of weathering:

1. Frost action:

Most things contract when they freeze but not water. Water

expands when it freezes into ice. Rain water seeps into tiny

cracks in rocks. When the water freezes it expands. The ice

presses against the sides of the cracks. The pressure is great.

It can make cracks bigger .

Activity:

In this activity you are going to see how water changes volume

when it freezes, and how rocks can be broken due to this.

Completely fill a small

glass jar (an old jam jar)

with water and screw on

the lid. Now place it in a

clear plastic bag, tie the

bag at the top and put it

into the freezer. Leave it

for 12 hours!. Do NOT

remove it from the plastic

bag.

71

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Describe and explain what happened!

__________________________________________________

__________________________________________________

__________________________________________________

__________________________________________________

__________________________________________________

Label this diagram and explain to your partner what is

happening! What do the arrows mean?

Temperature changes:

In most places it is warmer during the day than at night. Heat

expands rocks during the day. At night the rocks cool off and

contract. The expanding and contracting happen over and over

again. That strains the rocks. The strain makes them crack, a

tiny bit at a time.

Heat makes most things expand-get bigger.

Cold makes most things contract-get smaller.

72

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Animal activity:

Animals do not break rocks a part by themselves. But some

animals dig into the ground. Ants, worms, rodents etc. dig

holes. The holes let in air and water. The air and water

weather the rocks, breaking them into smaller pieces.

4. Wind:

Wind is sometimes strong enough to break particles of sand

from a rock. The sand may be carried by the wind. If the sand

hits another rock it will break even more particles, causing the

rock to wear away.

73

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

5. Water:

a. When rain hits the rocks it breaks it into small pieces, you

see the lines the water has made as it moves..

• b. Around the world, moving water picks up and transports

millions of tonnes of sediment every day, along rivers,

coasts, and even in the deep oceans.

74

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Key words:

Weathering

Frost

Expand

Contract

Do you know?

The Mississippi river carries over 500 million tonnes of

sediment to the sea each year!!

Grains are worn smooth as the water carries them

along. That’s why beach sand is smoother than river

sand.

Project:

Make a poster for the causes of weathering showing

pictures for each cause. Include, CLEAR TITLE, explain the

different types of weathering using pictures and diagrams!

Make it look nice, use big writing and don’t forget your

names!!

Key Ideas:

- Weathering is the breaking

down rocks into small pieces.

- Temperature, frost, animals,

wind and water, help to

weather rocks.

- Expand: to become bigger

- Contract: to become smaller

- Rocks are a solid part of the

Earth.

- Earth is a rock

75

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Key questions:

Q1: What does weathering mean?

…………………………………………………………………………………………………

……………………………………………………………………………………………….

Q2: List three causes of weathering the rocks:

1. …………………………………………………………

2. …………………………………………………………

3. …………………………………………………………

Q3: Describe how weathering takes place by water.

…………………………………………………………………………………………………

…………………………………………………………………………………………………

Q4: Explain why many stones found in streams and in

the sea are smooth.

…………………………………………………………………………………………………

…………………………………………………………………………………………………

76

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Soil

Now we know how big rocks get broken into smaller pieces and

how these smaller pieces are moved about by water or wind.

Soil is basically the collection of these small pieces!

Have you ever played in a sandbox? Would you believe that all

that sand was once big rock?

Soil is of different types depending on the areas...

What kind of soil is this? Write the type next to it!

Soil is formed from small pieces of rock

5.11.4

77

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Soil is produced when rocks are broken down into small pieces

by weathering.

The type of soil depends on

the type of rock from which

it was made.

Soils from different rocks

have different physical

characteristics and

properties.

Investigating soil properties:

1. Examine with hand lens:

Examine different soils under a

magnifying glass look at particle

size, colour, and texture and at

any rotting organic matter.

78

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

2. Particle size:

Activity:

Use a sieve to separate some different soils.

The soils should be dry and you should use the same sieve each

time to keep it a fair test.

My observation:

Soil (1) Soil (2) Soil (3)

particle size

Colour

texture

rotting organic

matter

79

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

2. Absorption and flow of water:

Activity:

1. Poke holes in the bottoms of three

plastic containers.

2. Put different type of soil in each container.

3. Pour water into the soil

4. Collect for 1 min the water which comes through the

container

Results: .........................................................

Most soils are one of three types:

1. Clay soil

2. Sandy soil

3. Humus soil

Soil Particles through the mesh Amount of water

80

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Clay holds water. Land with clay soil can be easily flooded.

Water runs quickly through sandy soil, thus plants may not

have enough water.

Humus soil is a dark coloured soil that develops as dead

plants and animals decay, when it can’t decay any further

it is called Humus.

Activity:

What is soil made of?

Put a sample of each soil in a clear

plastic drink bottle so that the bottle is

about half full.

Put water in the bottle until it is about

three-quarters full.

Put the top on and shake the bottle

hard. Then put it down and wait for it

to settle.

Look at how it has settled.

81

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Where are the stones?

----------------------------------------

Where are the big particles of soil?

----------------------------------------

Where is the fine (small pieces) soil?

----------------------------------------

What does the water above the soil look like?

----------------------------------------

Are there any bits that float?

----------------------------------------

If so what are they?

----------------------------------------

Draw a picture of the results and describes the main

layers of the soil in the box.

82

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Type of soil Sandy Clay Humus

Colour of soil light Dark Little dark

Size Large Small Medium

Texture Rough Smooth Smooth &

rough

Time for water to

pass through

Fast Slow Medium

Drawing the

particles

83

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

What is ‘good soil’?

Good soil is made through the combination of erosion by rivers

and biological processes that puts humus into the soil.

A good soil has:

1- humus which is important to hold water in the soil.

2- has quite large soil particles, a soil with fine particles

does not drain well.

3- spaces for air, the plant roots and other living things in

the soil need air.

Key words:

Soil

Clay

Loam

Sandy

Do you know?

Earthworms burrow through the

soil. As they move, they turn over

soil better for farming.

Project:

Go in a trip with your teacher and

try to collect different types of

soil, classify them into

1. Loam soil

2. Clay soil

3. Sandy soil

Key Ideas:

Soil is small

pieces of rock.

Soil is classified

into 3 types:

1. Clay soil

2. Loam soil

3. Sandy soil

84

Earth and space

Grade 5, Unit 5E.1:

Rocks and how we use them

Key questions:

Q1: Which type of soil is the best for plants? Why?

------------------------------------------------

----------------------------------------------

Q2: Compare between the three types of soil:

Characteristic Sandy soil Loam soil Clay soil

Color

Texture

Explain why water sinks slowly through soils that are made

of fine particles but quickly through sandy soils that are

made of larger particles.

…………………………………………………………………………………………………………………

Explain why the valleys of the Nile and the Tigris and

Euphrates are rich agricultural areas and explain the

origins of the sand deserts in the Arabian Peninsula.

…………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………

……………………………………………………………………………………………………………….