Why do the shape and size of a balloon change when filled with air or water ?

Explanation

To understand why the shape and size of a balloon change when filled with air or water, we can break it down into a few steps:

### Step-by-Step Solution:

1. **Understanding the Balloon**: A balloon is made of elastic material that can stretch. When you fill a balloon with air or water, you are adding a substance that takes up space.

2. **Filling with Air**: When you fill a balloon with air, the air molecules inside the balloon push against the walls of the balloon. This pressure causes the balloon to expand. The more air you add, the more the balloon stretches, increasing its size.

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