1.
creature
10 Key Points to Preview with a Summary
Q.01 Between cherries and ginkgo nuts, which one has edible seeds? 13
Q.02 Why don't fruits and crops grow well when they don't get enough water or sunlight?
Q.03 Which do plants need: carbon dioxide or oxygen? 17
Q.04 Why do all leaves have veins like blood vessels? 19
Q.05 Where does the water absorbed by plants through their roots go? 21
Q.06 Why don't ferns and mosses bloom? 23
Q.07 Which has more petals, cherry blossoms or dandelions? 25
Q.08 Why are the bodies of humans and cats soft, but the bodies of plants hard? 27
Q.09 Why does saliva come out when food enters the mouth? 29
Q.10 Why are nutrients in food efficiently absorbed in the small intestine? 31
Q.11 Why do our lungs expand when we breathe in? 33
Q.12 Why does my heart keep pounding? 35
Q.13 Why is blood red? 37
Q.14 Why does the lower leg pop up when you hit below the knee? 39
Q.15 Why are animals less visible in winter? 41
Q.16 Why are frogs, turtles, and humans all said to have evolved from the same ancestor?
Q.17 What force causes plant roots to grow? 45
Q.18 Do animals need a male and female to produce offspring? 47
Q.19 How do paramecium beetles produce offspring if they don't have males or females?
Q.20 Why aren't children's faces and bodies exactly like their parents'?
Q.21 Why are there so many insects and plants, but so few lions and eagles?
Q.22 Why do bird carcasses and fallen leaves disappear over time? 55
Q.23 Why does temperature rise when carbon dioxide in the air increases? 57
Verification Test 59
Five Questions to Deepen Your Understanding of Principles 61

2.
chemistry
66 Key Points Previewed with Formulas and Chemical Formulas
Q.01 Why does carbon dioxide always form when wood or candles burn?
Q.02 Ice and water are the same substance, so why does ice float on water? 71
Q.03 Why can't oxygen and ammonia be collected in the same way?
Q.04 Why are sugar and salt invisible when dissolved in water?
Q.05 Why do crystals form in seemingly empty aqueous solutions? 77
Q.06 Why do solids and liquids expand in volume when they become gases? 79
Q.07 Why is crystals extracted from aqueous solutions by filtration? 81
Q.08 Why does pancake batter rise when baking soda is added? 83
Q.09: To decompose water, do you need to boil it? Or do you need to apply electricity to it? 85
Q.10 What is the difference between atoms and molecules? 87
Q.11 Why do bicycle handlebars and chains rust?
Q.12 Why does reddish copper appear when carbon is added to black copper oxide and heated? 91
Q.13 When iron meets oxygen, it becomes iron oxide.
What happens when iron meets sulfur? 93
Q.14 Why does burning charcoal leave only light ash, but burning metal makes it heavier?
Q.15 Why does electricity not flow through sugar water, but through salt water? 97
Q.16 Why does a battery form when two different metal plates are placed in hydrochloric acid?
Q.17 How do you distinguish between acidity and alkalinity? 101
Q.18 Why does water form when acidic and basic solutions are mixed? 103
Verification Test 105
Five Questions to Deepen Your Understanding of Principles 107

3.
Physics
112 Key Points Previewed with Formulas and Laws
Q.01 Why is the landscape so clearly reflected on the water surface? 115
Q.02 Why does a straw appear bent when placed in water? 117
Q.03 Why do distant objects appear upside down when viewed through a magnifying glass? 119
Q.04 Why does lightning flash first and thunder sound later? 121
Q.05 What is the difference between weight and mass? 123
Q.06 Why don't my feet sink into the snow when I wear skis? 125
Q.07 Why do candy bags swell when you climb a high mountain? 127
Q.08 Why does my body float in the ocean or pool? 129
Q.09 What is the difference between current and voltage? 131
Q.10 Why can't ammeters be connected in parallel and voltmeters in series? 133
Q.11 When connecting two small light bulbs to a battery, why is the light brighter when connected in parallel rather than in series? 135
Q.12 Why can I use multiple home appliances at once? 137
Q.13 Why does lightning strike? 139
Q.14 Why doesn't a compass point north near a current-carrying area?
Q.15 Why does a current-carrying wire move in a magnetic field? 143
Q.16 Why does electricity generate from magnets and coils? 145
Q.17 When an object is not moving, does that mean no force is acting on it? 147
Q.18 Why does a bicycle going down a slope gain speed if it doesn't brake? 149
Q.19 If you throw a ball in space, how will it fly? 151
Q.20 Why can a rocket ascend? 153
Q.21. A crane moves sideways while carrying rebar. Why isn't that "work"? 155
Q.22 Why does using a pulley make lifting easier? 157
Q.23 Why can roller coasters go up and down without engines? 159
Verification Test 161
Five Questions to Deepen Your Understanding of Principles 163

4.
Earth Science
168 Key Points to Preview with a Summary
Q.01 Why do volcanoes erupt? 171
Q.02 What kind of rock does magma become when it cools and solidifies? 173
Q.03 Why do earthquakes occur frequently in Japan? 175
Q.04 Why do earthquakes produce two tremors? 177
Q.05 Why are the cliff strata striped? 179
Q.06 Why do bent or misaligned strata form? 181
Q.07 Why do fossils form? 183
Q.08 Why can we discern situations from very distant times through geological layers? 185
Q.09 Why doesn't my laundry dry well on rainy or cloudy days? 187
Q.10 When air rises, clouds form.
Why is that? 189
Q.11 Why is the weather cloudy under low pressure?
Q.12 Why does thunder and rain fall when a cold front passes through? 193
Q.13 Why do dry, cold northwesterly winds blow in winter and humid southeasterly winds blow in summer? 195
Q.14 Why does it rain continuously during the rainy season? 197
Q.15 Why is spring and fall weather so unpredictable? 199
Q.16 Why does the phenomenon of rapid temperature rise occur? 201
Q.17 Why does a typhoon moving west suddenly change direction and approach Japan?
Q.18 Why do the sun, moon, and stars all rise in the east and set in the west? 205
Q.19 There is a stationary star in the northern sky.
Why won't it move? 207
Q.20 Why does the time at which constellations begin to appear on the horizon continually change?
Q.21 Why isn't Orion visible in summer?
Q.22 Why does the sun's altitude rise in summer and fall in winter? 213
Q.23 Why does the moon change shape every day? 215
Q.24 The moon is much smaller than the sun, so why is the sun covered by the moon during a solar eclipse? 217
Q.25 Why is Venus only visible in the evening or early morning?
Q.26 How do we know that the sun is a spherical solid? 221
Verification Test 223
Five Questions to Deepen Your Understanding of Principles 225

Verification Test Answers and Explanations 229

110 Science Principles Every Middle School Student Should Know from Textbooks
Let's have fun learning by asking and answering questions!
Real scientific skills developed through principles!

The reason many young people find science boring is largely due to rote learning.
Knowledge that you memorize without any reason to prepare for a test is quickly forgotten and is no fun.
This type of learning only increases the distance from science.


"Questioning Science Lab" poses questions about phenomena that can be easily observed in everyday life.
The 110 questions and answers contain the scientific principles behind why the phenomenon occurs.


“Why does lightning flash first and thunder come later?” “Why does saliva come out when we chew food?” “Even though ice and water are the same substance, why does ice float on water?”

These questions may seem trivial, but they contain important scientific principles such as the difference between the speed of light and sound, unconscious reactions, and the properties of matter.
Through this process of asking questions and finding answers, we can realize that the various phenomena around us are in fact all science, and we can experience the fun of asking questions.
By actively answering questions and understanding the principles, the context of previously fragmented knowledge will be connected, and scientific knowledge will be easily engraved in your head without having to memorize it.
In addition, you will build up real scientific skills that will allow you to easily solve difficult problems.


A smart learning book tailored just for teenagers

Current science teachers unanimously agree that this book is essential for schools.
"Questioning Science Lab" covers all four fields of biology, chemistry, physics, and earth science in one volume, making it ideal for elementary and middle school students preparing for "integrated science."
Because it is possible to study by dividing it into fields, it is also suitable for previewing science, which is learned as an elective subject in high school.


Above all, this book is closely linked to the elementary and middle school curriculum.
As you ask and answer questions, the essential scientific principles that appear in textbooks will naturally accumulate in your head.
Thanks to its comprehensive curriculum, teachers and students can fully utilize the questions in this book when preparing science discussion classes.


This book provides a summary before beginning the full-scale Q&A.
You can preview important content or come back for hints if you get stuck on a quiz.
Additionally, after answering all the questions in each field, you can check what you have learned by solving science problems that are easy to get wrong or frequently appear on exams in the 'Confirmation Test'.
You can learn more in-depth content in 'Five Questions to Dig Deeper'.
『Questioning Science Lab』 has content and structure that are perfectly suited to the learning patterns of young people.


Let's get rid of the prejudice that science books are boring.
A cute and quirky science book!

"Questioning Science Lab" doesn't give you a moment to be bored.
The 110 questions and answers, which contain only the essential key points and are presented quickly and concisely, are perfect for students to read during their breaks.
The two main characters leading this question and answer conversation are ‘Principle Group’ and ‘Teacher Lee Hae.’
The charming principle group that asks absurd but sometimes sparkling questions, and the conversation between 'Teacher Lee Hae' who wittily answers even the most absurd questions, are sometimes so entertaining that they make you burst out laughing.


Each question and answer is accompanied by rich illustrations.
Cute illustrations of scientific phenomena around us not only help readers understand the content, but also make science more approachable and fun.
Through this book, you will be able to break free from the prejudice that science books are cold and rigid and experience the joy of science.