When I dragged the ballon to the wall, the negative blue charges moved away. However when I moved it to the sweater, the ballon was attracted to it. This is because the negative charges are attracted to the positive charges repel from the negative charges
Based on your description, it sounds like you're experiencing static electricity effects where different materials either gain or lose electrons through friction when they come into contact with each other. When you rub a balloon against a wall, it can become charged with static electricity.
If the balloon picks up extra electrons, it becomes negatively charged. When you then bring the negatively charged balloon close to the wall, the negative charges in the wall's surface can move slightly away if the wall is made of a conductive material. This can leave a slightly positively charged area on the surface of the wall due to the negative charges moving away from the area closest to the balloon. The balloon is attracted to this area because opposite charges attract.
When you move it to the sweater, the opposite happens. Depending on the material of the sweater, rubbing the balloon might have caused the sweater to pick up a positive charge (by losing electrons) or the balloon to pick up more negative charges. If the sweater is positively charged (less negative than the balloon), the balloon will be attracted to it because, again, opposite charges attract.
In essence, the balloon is either repelled from or attracted to surfaces based on the distribution of charges. This phenomenon is governed by the principle that like charges repel and unlike charges attract.
Now take that same balloon and drag it over to the wall. You will notice that the blue negative charges move away in the wall and then the balloon sticks to the wall. This charge distribution is called induction, because the negative charges move without any touching. Why does the balloon stick to the wall?
The balloon sticks to the wall due to a process called electrostatic induction. Here's what happens step by step:
1. **Charging the Balloon**: When you rub the balloon against another material, such as your hair or a sweater, electrons are transferred from one material to the other. If the balloon gains electrons, it becomes negatively charged.
2. **Approaching the Wall**: As you bring the negatively charged balloon close to the wall, the electric field from the balloon exerts a force on the charges within the wall.
3. **Induction in the Wall**: If the wall is made of a material that allows some movement of electrons (not a good conductor like metal, but not a perfect insulator either), the negative charges in the wall (which could be electrons in the atoms or molecules making up the paint or plaster) are repelled by the negatively charged balloon. The electrons move slightly away from the surface closest to the balloon, creating a negatively charged area slightly farther away and a positively charged area on the surface.
4. **Attraction**: Opposite charges attract, so the induced positive charge on the wall's surface gets attracted to the balloon's negative charge. This electrostatic attraction is strong enough to counteract the force of gravity on the lightweight balloon, allowing it to stick to the wall.
5. **Adhesion**: The balloon sticks to the wall due to the electrostatic force between the induced positive charges on the wall's surface and the negative charges on the balloon. These attractive forces across the surface of contact create enough adhesion for the balloon to defy gravity temporarily.
The balloon will remain stuck to the wall until the charges redistribute (the wall and the balloon reach equilibrium) or until external forces like air currents or gravity overcome the electrostatic attraction.
That's an interesting observation! The behavior you described can be explained by the principles of electric charges.
The balloon you dragged on the wall becomes charged, usually negatively. Conversely, the sweater can become charged positively. This occurs due to a process called triboelectric charging, which happens when two objects come into contact and transfer electrons between each other.
In the case of the balloon and the wall, the negative charges on the balloon repel the negative charges on the wall, causing them to move away. This creates an area of positive charge on the wall, attracting the negatively charged balloon.
On the other hand, when you brought the balloon close to the sweater, the negative charges on the balloon are attracted to the positive charges on the sweater. Positive and negative charges attract each other, so the balloon is pulled toward the sweater.
To summarize, the behavior you observed is due to the fact that opposite charges attract each other (positive and negative), while like charges repel each other (positive and positive, or negative and negative). This fundamental principle of electric charges explains the interaction between the balloon and the wall or the sweater.