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Investigating solids and why they keep their shape no matter where we put them.
Have you ever wondered why your favorite toy brick stays like a brick whether it's in your pocket or on your bed, but juice splashes and spreads everywhere?
Everything in our world is made of matter. A solid is a special kind of matter that has its own shape. Think about a wooden block. If you put that block in a round bowl, does it turn into a circle? No! It stays a square block. This is because the tiny pieces inside a solid are packed very tightly together. They are like friends holding hands so tightly that they cannot slide past each other. Because they stay put, the solid keeps the same shape no matter where you put it.
Quick Check
If you move a toy car from a small box to a big bucket, does the car change its shape?
Answer
No, the car stays the same shape because it is a solid.
Look around you! Most of the things you use every day are solids. Your desk, your shoes, and even your toothbrush are solids. Some solids are very hard, like a rock. Other solids can be a little bit soft, like a sponge or a teddy bear. Even if a solid is soft, it is still a solid because it doesn't move away or disappear when you leave it alone on a table. It has a fixed volume, which means it takes up the same amount of space.
Let's see if a pencil is a solid: 1. Pick up 1 pencil. 2. Lay it flat on your desk. It looks like a long stick. 3. Stand it up in a tall cup. It still looks like a long stick. 4. Result: The pencil kept its shape, so it is a solid!
Quick Check
Is a piece of paper a solid even though you can fold it?
Answer
Yes, it is a solid because it does not flow like water and it stays in its shape unless you move it.
The biggest difference between a solid and a liquid is flow. Liquids, like water or rain, love to slide and spread out. If you pour water on a table, it makes a big puddle. But if you put a pile of coins on a table, they stay right where they are. They do not flow or run off the edges. Solids stay together in a group because their parts are locked in place.
Imagine you have two containers: 1. Container A has marbles (solids). 2. Container B has cup of milk (liquid). 3. If you tip Container A, the marbles might fall out, but each marble stays a round ball. 4. If you tip Container B, the milk spreads out and changes shape to cover the floor.
Is Play-Doh a solid if you can change its shape with your hands? 1. Take a ball of clay. It is a solid. 2. Use your hands to squash it flat. 3. The shape changed, but only because you pushed it. 4. If you leave the flat clay on the table, it stays flat. It doesn't crawl away or turn into a puddle. Therefore, it is still a solid!
Which of these is a solid?
What happens to a solid's shape when you put it in a new container?
A soft pillow is a solid.
Review Tomorrow
Tomorrow morning, try to find 3 solids on your breakfast table. Do they keep their shape?
Practice Activity
Go on a 'Solid Hunt'! Find one solid that is hard, one that is soft, and one that is heavy. Check if any of them can flow like water (Hint: They shouldn't!).