Centimetres and/or millimetres - depending on the size of the piece !
A piece of chalk is an insulator. It does not conduct electricity due to its high resistance to the flow of electrical current.
Crushing a piece of chalk breaks it down into smaller particles, typically creating a powdery substance.
Crushing a piece of chalk is only a physical change. Chemically, it is still chalk.
It is a fraction of the length of a piece of string!
You can demonstrate that a piece of chalk has mass by weighing it on a scale. Place the chalk on the scale and observe the reading, which indicates the gravitational force acting on the chalk due to its mass. A non-zero reading confirms that the chalk has mass.
With every stroke of the chalk piece it leaves some of the chalk on the board. This abrasion of the piece of chalk causes it to wear down. This is similar to why the rubber tyres of cars wear down when they are driven over a road surface.
When a piece of chalk is broken into pieces, there is a physical change as the chalk is simply being divided into smaller fragments. The chemical composition of the chalk remains the same even though it is now in multiple pieces.
A chalkboard is a piece of slate on which to write with chalk and is named after the color "black".
A rubber band would be more easily broken than a piece of chalk or a skirt. Rubber bands are designed to stretch and be flexible, making them more likely to break when stretched beyond their limits. A piece of chalk is more rigid and a skirt is made of fabric, which are not as easily broken by stretching or bending.
A piece of chalk is called matter because it is made up of atoms and molecules, which are the building blocks of all matter in the universe. In this case, the chalk is composed of materials such as calcium carbonate and other compounds that give it its physical properties.
Chalk is "de la craie" when you are considering the rock. A piece of chalk is "une craie" (fem.) The expressions: - Not by a long chalk = Loin s'en faut - By a long chalk = De loin