rocks and soil

Earth is made of materials that have distinct properties and provide resources for human activities.. Students know how to compare the physical properties of different kinds of rocks

Genre Comprehension Skill Text Features Science Content

Nonfi ction Draw Conclusions • Captions

• Labels

• Glossary

Natural Resources

Scott Foresman Science 2.6

Standards Preview

Standard Set 3 Earth Sciences

3 Earth is made of materials that

have distinct properties and provide

resources for human activities As the

basis for understanding this concept:

3.a Students know how to compare

the physical properties of different

kinds of rocks and know that rock is

composed of different combinations

of minerals

3.b Students know smaller rocks come

from the breakage and weathering of

larger rocks.

3.c Students know that soil is made

partly from weathered rock and partly from organic materials and that soils differ in their color, texture, capacity

to retain water, and ability to support the growth of many kinds of plants.

3.e Students know rock, water, plants,

and soil provide many resources, including food, fuel, and building materials, that humans use.

ISBN 0-328-23510-5

ì<(sk$m)=cdfbaa< +^-Ä-U-Ä-U

Earth Sciences

by Mary Beth Spann

fuel

luster

minerals

natural resources

rock

soil

weathering

Picture Credits

Every effort has been made to secure permission and provide appropriate credit for photographic material The

publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.

Unless otherwise acknowledged, all photographs are the copyright of Dorling Kindersley, a division of Pearson.

ISBN: 0-328-23510-5

Copyright © Pearson Education, Inc All Rights Reserved Printed in the United States of America

This publication is protected by Copyright, and permission should be obtained from the publisher prior to any

prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic,

mechanical, photocopying, recording, or likewise For information regarding permission(s), write to

Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025.

1 2 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06

by Mary Beth Spann

What are rocks

and minerals?

Rocks are all over the place!

They are in your backyard

They are at the beach and in the forest

A rock is the hard, solid part of the

Earth that is not soil or metal

How are these rocks different?

<PHOTO: Lake from SE p 172>

3

Rocks can be different sizes and colors

Some are small and light

Others are large and heavy

These rocks are found

at Mono Lake, California.

Minerals

Minerals make up rocks

Minerals are nonliving materials that

come from Earth

Gold, silver, and iron are all minerals

We make rings, coins, and nails from

minerals

This mineral is silver

We make coins and jewelry from silver.

5

Most rocks have several minerals

The rock on this page is granite

Granite has three minerals

They are quartz, feldspar, and mica

You can see the minerals in the granite

Granite

Properties of Minerals

Minerals have properties

A property is something about an object

that you can observe

Some minerals are hard

Others are soft

Hardness is a property of minerals

Diamond is the

hardest mineral

It can scratch glass

Talc is a soft mineral You can scratch it

7

Color is another property of minerals

So is luster

Luster is how shiny or dull a mineral is

Limonite’s luster is dull

Azurite’s luster is shiny

Azurite

What is

weathering?

Weathering is the breaking apart and

changing of rocks

Weathering can change a rock’s size

It can change a rock’s color and shape

Weathering can make rocks smaller

Rocks can be changed

by weathering

9

Changes in temperature can weather rocks

Water can fl ow into cracks in rocks

When it freezes, the rocks break apart

Plants can also cause weathering

Their roots can grow into cracks and break rocks apart

Small rocks Gravel Sand

Other Causes of Weathering

Look at the picture below

Water dissolved rock

The water washed the rock away

Dripping water made shapes in

the cave

Weathering also

happens in caves.

11

Some rocks have iron in them

The iron can mix with air when the rocks get wet

Rust forms on the rocks

The rocks turn reddish brown

The rust weakens the rocks

The rocks may break apart

Rust can weather rocks.

What is soil?

Soil is the top layer of Earth

Plants need soil to grow

Look at the picture below

Many things make up the soil

Worms loosen

and mix the soil.

13

Soil is full of weathered rock

It also has leaves and twigs in it

Soil has parts of living things that died

Soil changes when animals dig in it

Animals loosen and mix it as they dig

This gopher loosens and mixes soil.

Kinds of Soil

Different plants grow best in different

soils

Sandy soils hold water poorly

Most plants do not grow well in them

Clay soils hold water well

But some plants cannot grow in them

Iron makes some clay soils red

Clay soil is smooth

It also feels soft and sticky

15

Most plants grow well in loam

Loam is good at holding water

Plants that grow in loam get the water they need

Loam has parts of plants and animals that have died

What are natural

resources?

Resources are things we use

Natural resources are useful

materials that come from Earth

They include soil, water, rocks,

and plants

Cotton is a resource

It is used to make clothes.

17

Natural resources meet our needs

They give us food, clothing, shelter, and fuel

We use rocks to build things

We use soil to grow plants for food

We use plants for fuel and to build things

Water is a natural resource Living things need water.

Other Natural Resources

Rocks are a natural resource

We use rocks to build things

We can mix rocks with sand, cement,

and water

This makes concrete

Concrete is used for roads, sidewalks,

and steps

Concrete steps

19

Wood is a natural resource

Oil and gas are also natural resources

We use these things for fuel

Fuel is anything that is burned to make

heat or power

This fi replace uses wood for fuel

to make heat or power

mineral is

come from Earth

natural resources useful materials that

come from Earth

Earth that is not soil or metal

changing of rocks

1 What are some things people make from

minerals?

2 What three minerals does granite have?

limonite, hardness, diamond, luster, and azurite in this book Write some sentences that group these things into their proper relationships.

4 Draw Conclusions If you found some

rocks that were reddish brown with rust on them, what might you conclude?