because it is soft,rough,white and is shown clearly when writing
Chalk is good for writing on a hard surface because it is a soft and powdery substance that can easily adhere to the surface, creating visible marks. It also offers good contrast against dark backgrounds and can easily be erased or smudged off, making it a convenient tool for temporary or quick writing.
slate
Slate
help me pls
You can write on rocks or hard surfaces like slate, granite, or concrete using a variety of tools such as chalk, charcoal, or markers specifically designed for use on these surfaces. Using a flat, smooth rock or surface will provide the best results for writing. Avoid using sharp objects that can scratch the surface.
clodudy
Chalk is a soft, sedimentary rock composed primarily of calcium carbonate, used for writing and drawing. Coal is a hard, dark, combustible rock formed from decayed plant matter, used as a fuel source. chalk is used for writing and coal is used for energy production.
There are a couple of things that make chalk hard. The calcium in chalk is said to make chalk hard.
No it is not
Bjorn Borg was good at playing tennis on non-hard surfaces.
The problem likely lies with the chalk itself. A lot of chalk you buy today, especially cheap chalk, is too hard to use on chalkboards with any kind of good result. Try a different brand of chalk, one that is softer.
2.hard 3.harder