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160 What Is Dust Made Of?
Dust is made of many tiny things. In houses, it has skin cells, hairs, pet dander, and threads from clothes. Dust mites live in dust and eat dead skin and fungi. Each home’s dust is unique because i...
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135 Where Do We Get Fresh Water?
Our bodies are mostly water, and fresh water is essential for life. However, only 2.5% of Earth’s water is fresh, and even less is easily usable. Fresh water includes surface water, ice caps, and gr...
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152 Photosynthesis and Food
Most of the food we eat, like fruits and pasta, contains carbohydrates made of carbon, hydrogen, and oxygen. These atoms come from air, water, and sunlight through photosynthesis in plants.
Plants ...
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145 Why Do Fingers Wrinkle in Water?
When fingers get wet, they wrinkle, a phenomenon scientists have studied for decades. In the 1930s, doctors noticed that people with hand nerve damage did not get wrinkly fingers, suggesting that wrin...
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176 Why Do Seasons Change?
Seasons change because of Earth's tilt, not its distance from the sun. Earth's orbit is almost circular, so the distance from the sun changes only slightly. In fact, Earth is closer to the sun in Janu...
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179 What’s Below the Tip of the Iceberg?
Icebergs are mostly underwater because ice is less dense than seawater. About 1/9 of an iceberg is above the surface, and the rest remains hidden. Icebergs form when glaciers, made of compressed fresh...
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145 The Perilous Journey of Migrating Birds
Each spring, many songbirds return from Central and South America. They travel up to 7,000 miles to breed. Before leaving, birds eat a lot to store energy. While flying, they lose weight quickly.
T...
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172 The life of Penguins.
Penguins are loved worldwide for their charm but face many dangers. Unlike flying birds, they have evolved to swim fast and dive deep with their flipper-like wings and solid bones. Penguins live in th...
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141 Coelacanth: The Living Fossil
The coelacanth, a fish thought to have gone extinct 65 million years ago, was rediscovered in 1938 near South Africa. This "living fossil" has barely changed in 300 million years. Later, a second spec...
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128 Why Elephants Never Forget
The saying “elephants never forget” is scientifically accurate. Elephants can recognize up to 30 herd members and remember other animals and humans for decades. Their large brain, comparable to a ...
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144 How Do We Breathe?
Breathing keeps us alive by delivering oxygen to our bodies. Air enters through the nose or mouth and moves to the lungs' alveoli, where oxygen is absorbed into the blood. The diaphragm and intercosta...
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135 Why Mosquitoes Bite Some People More
Mosquitoes prefer some people over others due to several factors. Female mosquitoes feed on blood to support egg production and use specialized sensors to detect their preferred hosts. They are attrac...
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145 How Did Museums Begin?
Museums have a history of over 2,000 years, evolving greatly from their origins. The word "museum" comes from the Greek "mouseion," temples for the Muses, where offerings like sculptures and scientifi...
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162 A Brief History of Plastic
Plastics originated from the need to replace materials like ivory in the 19th century. In 1863, John Wesley Hyatt invented celluloid, the first plastic, made from cellulose. Although celluloid was fla...
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146 Why Can’t You Put Metal in a Microwave?
Microwave ovens use electromagnetic waves to heat food by making polar molecules, like water, vibrate and create frictional heat. This technology, originally developed for RADAR in World War II, doesn...
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128 What Happens If You Don’t Put Your Phone in Airp...
Phones emit strong radio wave signals to connect with cell towers. In flight, phones work harder to find service due to the distance from towers, broadcasting loud signals that can overwhelm ground co...
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141 Were Long Necks Also Tall Necks?
Sauropod dinosaurs, known for their incredibly long necks, raise questions about how these necks were positioned—vertically, horizontally, or somewhere in between. Paleontologists debate this be...
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145 Did Dinosaurs Really Have Feathers?
Scientists have confirmed that many dinosaurs, especially theropods like Velociraptors and possibly T. Rex, had feathers. Fossils discovered over the past 20 years, especially in China, show clear evi...
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149 Why Do Cats Purr?
Cats purr by using their larynx and diaphragm muscles, creating rhythmic vibrations between 25 and 150 hertz during inhaling and exhaling. While purring is often associated with happiness, cats also p...
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176 Why Mammals Are Smaller Than Dinosaurs
Long ago, dinosaurs grew very big. One dinosaur, Amphicoelias Fragillimus, was 60 meters long and weighed 122 tons. Today, the biggest land mammal is the African elephant. It is only 5.5 tons and 3-4 ...
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141 Bananas: Not What They Seem
Bananas are popular and nutritious fruits that people love for their convenience. However, bananas today are not like wild bananas. Wild bananas have seeds, but the bananas we eat, like the Cavendish,...
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170 Why Sleep Is Essential
Sleep is something everyone needs, but scientists still do not fully understand why. Sleep helps our brains and bodies rest and recover. It may also help us survive by keeping us safe and saving energ...
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181 What Happens When You Stop Eating
Starvation happens when the body doesn’t get enough food. Without oxygen, people die in minutes. Without water, they last a few days. But without food, a person can survive for weeks or even two mon...
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141 How Oysters Make Pearls
Pearls are not mined from the earth but made inside oysters. This happens when something small, like a bit of food, gets trapped between the oyster’s soft tissue and hard shell. This irritates the o...
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187 Do We Only Use 10% of Our Brain?
People often say humans use only 10% of their brains. This idea is popular in movies and speeches, but it is not true. Scientists have proven that we use every part of our brain.
Brain scans like M...
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