Information about chalk sticking to blackboard

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In summary, chalk nowadays is made up of calcium sulfate rather than calcium carbonate. There is currently no data on the spectral lines of calcium sulfate, but combining the spectral lines of calcium, sulfur, and oxygen may create the spectral lines of the original molecule. The adhesion between chalk and blackboard is due to electrostatic force, which is induced by friction on the chalk powder when writing on the blackboard. This can potentially be proven or disproven through experiments using a Van de Graaff generator.
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whyme1010
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So chalk nowadays is made up of calcium sulfate rather than calcium carbonate. I want to know if there exists any data on spectral lines of calcium sulfate. If not, does combining the spectral lines of calcium sulfur, and oxygen create the spectral lines of the original molecule?

Why does chalk stick to blackboard? The chalk fills in the tiny gaps in whatever board you may be using, but I'm interested in how this solid-solid adhesion works.
 
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I suppose it is due to electrostatic force. When writing on the blackboard, there is charge induced by friction on the chalk powder, thereby sticking to the metallic blackboard.

But this is just a conjecture. Maybe you can (dis)prove it by experiments using a Van de Graaff generator?
 

1. Why does chalk stick to blackboards?

Chalk sticks to blackboards because of adhesion, which is the attractive force between two different materials. The rough surface of the chalk and the porous nature of the blackboard create a strong adhesion, causing the chalk to stick.

2. How can I prevent chalk from sticking to my blackboard?

To prevent chalk from sticking to your blackboard, you can lightly dampen the surface with a wet cloth and then wipe it dry. This will create a smoother surface and reduce the adhesion between the chalk and the blackboard. Another option is to use a chalkboard cleaner or a microfiber cloth to remove any excess chalk residue.

3. Does the type of chalk affect how much it sticks to a blackboard?

Yes, the type of chalk can affect how much it sticks to a blackboard. Traditional chalk, also known as calcium carbonate, tends to stick more because of its rough texture. However, newer types of chalk such as liquid chalk or chalk markers have a smoother texture and may not stick as much to a blackboard.

4. Why does chalk sometimes make a screeching sound on a blackboard?

The screeching sound that chalk makes on a blackboard is due to the friction between the chalk and the blackboard surface. When the chalk is dragged across the rough surface, it creates vibrations that we perceive as a screeching sound.

5. Can chalk stick to any other surfaces besides blackboards?

Chalk can stick to other surfaces besides blackboards, such as concrete, brick, or wood. This is because these surfaces also have a rough texture that allows for adhesion. However, chalk may not stick as well to smoother surfaces such as glass or metal.

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