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Finding examples of solid matter in the natural world like rocks and trees.
Why can you stand firmly on a big rock, but your foot falls right through a puddle of water? The secret lies in what makes a solid!
A solid is a type of matter that has its own shape. Think about a rock you find on a trail. Whether you put it in your pocket or leave it on the ground, it stays the same shape. It doesn't spread out or leak away! This happens because the tiny 'building blocks' inside the rock are packed very tightly together. They are like a crowd of people standing shoulder-to-shoulder who refuse to move. In nature, things like stones, tree trunks, and acorns are all solids because they hold their form.
Quick Check
If you move a small stone from the ground into a round bowl, does the stone change its shape to look like the bowl?
Answer
No, it stays the same shape because it is a solid.
Not all solids feel the same! Some solids are very hard, like a granite mountain or a fallen log. You cannot easily change their shape by squeezing them. However, some solids are soft. Think of a dry sponge or a patch of fuzzy moss on a tree. Even though you can squish them with your hand, they are still solids! They don't flow like a river. If you stop squeezing a sponge, it tries to stay in its solid shape. Whether hard or soft, they all have one thing in common: they don't pour!
Let's compare two things you might find on a nature walk: 1. Pick up a pebble. Try to squeeze it. It does not change. This is a hard solid. 2. Pick up a dry leaf. You can crinkle it and change its shape, but it doesn't turn into a puddle. This is a soft solid.
Quick Check
Is a soft, fluffy bird feather a solid or a liquid?
Answer
It is a solid because it holds its own shape and does not flow.
Imagine you have marbles in a small box. If the box is packed so tight that the marbles cannot move, they stay in one block. This is how a solid works! A liquid, like water in a stream, has building blocks that can slide and dance past each other. That is why water flows downhill. But in a solid tree branch, the building blocks are locked in place. Because they are stuck together, the branch can't flow away. It stays right where the tree grew it!
Imagine placing different items into a cup: 1. If you pour cup of water in, it takes the shape of the cup. 2. If you put pinecone in, it stays shaped like a pinecone. 3. The pinecone is a solid because it keeps its own shape regardless of the container.
Think about a sandcastle: 1. You can pour sand out of a bucket, which makes it look like a liquid. 2. But look closer! Each tiny grain of sand is a tiny, hard solid. 3. A pile of sand is just thousands of tiny solids hanging out together!
Which of these is a solid you would find in the woods?
A solid must be hard to be called a solid.
Why does a wooden stick stay the same shape?
Review Tomorrow
Tomorrow morning, look around your room or backyard. Can you find solids that are hard and solid that is soft?
Practice Activity
Go on a 'Solid Scavenger Hunt!' Find one object made of wood, one made of stone, and one made of metal. Check if any of them can be poured like water (Hint: They shouldn't be able to!).