Question

a substance has no mass can we regard it has matter? why?​

Answer 1

Answer:

No we can't because all things called matter have mass

Answer 2

We cannot consider a massless substance as a matter. This is because the definition of matter states that a substance which has mass and can occupy some volume must be considered as matter. If a substance does not have either mass or volume or both of them, then we cannot consider it as matter.