A mixture of sugar and chalk is heterogeneous.
chalk is a compound
Chalk is not a mixture it is a chemical compound called Calcium carbonate.
chalk is a compound
Use a magnet to remove the iron filings from the mixture, then mix the remaining components with water. The copper sulfate will dissolve but the CaCO3 (chalk powder) will not. Filter the mixture to remove the chalk, then boil the water to recover the copper sulfate.
it is a mixture of white paint and white chalk
Chalk is Calcium Carbonate, aka CaCO3, so it's only one substance.
This is a suspension.
compound
You can add water to this mixture, which will dissolve the salt but not the chalk. Decant the water, then boil it away, and you will be left with salt.Salt is much more soluble in water than chalk is.
Chalk consists of calcium carbonate. It would be a heterogeneous mixture if colours were added to it.
Sublimation