© Pelangi Publishing (Thailand) Co., Ltd. 2019 All rights reserved. No part of this publication may be reproduced, stored in any retrieval system or transmitted in any form or by any means without permission of Pelangi Publishing (Thailand) Co., Ltd. 2019
Title Page.indd 1
ISBN 978-616-541-321-3 First Published 2562
14/12/2018 09:45
Contents Chapter 1 Plants 1 A
Needs of plants ................................................. 2
B
Care for plants ................................................... 8
C
Life cycles of flowering plants ........................... 10
Chapter 2 Living Things and Non-living Things 19 A
Living things ...................................................... 20
B
Non-living things ............................................... 21
C
Characteristics of living things and non-living things ................................................ 22
ii
Chapter 3 Materials
43
A
Physical properties of materials ........................ 44
B
Water absorbency ............................................. 54
C
Mixing materials ................................................ 60
D
Reusing used materials .................................... 66
Chapter 4 Light 74 A
What is light? .................................................... 75
B
How does light travel? ...................................... 78
C
Care for our eyes .............................................. 84
Chapter 5 Soil 90 A
Components of soil............................................ 91
B
Types of soil ...................................................... 94
C
Uses of soil ....................................................... 99
iii
Let’s Find Out !
Special features
Encourages students to find information and present their findings.
in this book STEM Activity Provides an activity that engages in the application of knowledge of scientists, mathematicians and engineers.
K.W. L .W Allows students to know what to look for while reading and to reflect on what they have learned.
Let’s Scan and Watch !
Let’s Think! Challenges students with questions that promote higher thinking skills.
Provides direct access to the relevant information on the Internet by scanning the QR codes given.
Helps students to master their scientific knowledge and skills.
Presents a powerful diagram to literally ‘map’ out all the concepts in the chapter.
4C’s of the 21st Century 4C’s The Skills are:
Let’s Laugh ! Makes learning science a fun thing.
Communication Sharing thoughts, questions, ideas and solutions. Collaboration Working together to reach a goal. Putting talent, expertise and smarts to work.
Let’s Know More ! Presents extra information that is relevant to the concept learned.
Critical Thinking Looking at problems in a new way and linking learning across subjects and disciplines.
Glossary
Creativity Trying new approaches to get things done equals innovation and invention.
Lists and explains difficult terms used in the text.
iv
Chapter
1
Plants The chili plants are growing healthily and producing many chilies. What do the chili plants need to grow well? How do we care for the plants? What is the life cycle of a chili plant?
K.W. L .W What do I know about plants? 1. 2.
K.W. L .W What else do I want to know about plants? 1. What do plants need to grow well? 2. How do we care for plants? 3. What is the life cycle of a flowering plant? 4.
Plants
1
A
g
in
n
io
tic
i
la b o r ati o
Cr
ol
m u nic at
C
Co
m
n
Needs of plants
al T hin k
Cr
e a ti v it y
Do plants need water? Things needed
Similar potted plants
1. Place two similar potted plants in the Sun. 2. Water one plant every day for two weeks. Label it as plant P. 3. Do not water the other plant for two weeks. Label it as plant Q.
PP
Q
Q
4. Observe the plants for two weeks. What do you notice after the first week and the second week? P: Q: 5. Did both plants receive the same amount of sunlight? 6. Which plant is not growing healthily? Explain. 7. What is your conclusion for this activity? 8. What is your evidence for your conclusion?
2
Science Prathomsuksa
2
Plants need water to grow. Without water, plants will wilt and die.
Suda waters her plant every day.
Suda’s plant is growing healthily.
Chet is too lazy to water his plant.
Chet’s plant is wilting.
Plants
3
Plants need the right amount of water for healthy growth.
Plants will wilt and die if they do not get enough water.
However, too much water is bad for plants too.
Let’s Think ! Why do plants die when their roots are in the water for too long?
4
Science Prathomsuksa
2
tic
g
in
n
n io
la b o r ati o
i
ol
Cr
m u nic at
C
Co
m
al T hin k
Cr
e a ti v it y
Do plants need sunlight? Things needed
Similar potted plants
Box
1. Place two similar potted plants in the Sun. 2. Cover one plant with a box. Label it as plant B. 3. Leave the other plant in the Sun. Label it as plant A. 4. Water them every day for two weeks.
AA
BB
5. Observe the plants for two weeks. What do you notice after the first week and the second week? A: B: 6. Did both plants receive the same amount of water?
7. Which plant is not growing healthily? Explain.
8. What is your conclusion for this activity?
9. What is your evidence for your conclusion?
Plants
5
Plants need sunlight to make food. Without sunlight for too long, the plants will not grow well and may die.
Are water and sunlight the only things that plants need? No, plants also need air to survive. Without air, plants will die. Air contains oxygen and carbon dioxide that plants need for survival. Plants need oxygen for respiration.
Plants need carbon dioxide to make food.
Let’s Know More ! Greenhouse farming is the production of crops in transparent structures. Here the growing conditions of crops such as sunlight and temperature can be controlled.
6
Science Prathomsuksa
2
Plants need nutrients to grow well. Soil has nutrients. Plants absorb the nutrients from the soil through the roots. The roots also absorb water from the soil.
Soil
Roots
To boost the growth of plants, we can add fertilizers to the soil. Fertilizers contain certain nutrients needed by the plants to grow better.
Fertilizers
Let’s Know More ! Farmers can also grow plants in solutions. These solutions are added with nutrients that a plant needs. We call this process of growing plants in solutions as hydroponics.
Plants
7
B
Care for plants
Plants are important to us. If you are growing some fruit trees and vegetables in your garden, you should…
plow the soil to loosen it. Roots grow easily in loosened soil.
water the plants if it had not been raining for a few days.
pull out weeds and control pests. The weeds and pests will affect the growth of your plants.
8
Science Prathomsuksa
2
add fertilizers occasionally to ensure the plants have enough nutrients to grow well.
If you are growing some potted plants, you should...
place the potted plants in areas with adequate sunlight. They need sunlight to make food.
water the potted plants regularly but not too much.
add fertilizers occasionally too.
Plants
9
C
tic
g
in
n
io
la b o r ati o
i
ol
Cr
m u nic at
C
Co
m
n
Life cycles of flowering plants
al T hin k
Cr
e a ti v it y
What is the life cycle of a mung bean? Things needed
Mung bean
Soil
Pot
Ruler
1. Put some soil into a pot. 2. Place the mung bean in the soil. Give some water to the mung bean in the soil. 3. Put the pot at a suitable place. 4. Observe the changes in the mung bean every week for a month and then once every month for the next 3 months. Draw a picture or take a photograph of the plant, measure its height with a ruler, count the number of leaves and describe the changes in the plant in the table below. How does the plant look like?
Date Week 1
Week 2
10
Science Prathomsuksa
2
Height of the plant
Number of leaves
Description
Week 3
Week 4
2nd month
3rd month
4th month
Plants
11