Question

why sun light is not called as matter​

Answer 1

Answer:

because it shows dual charestic it show behaviour as matter as well as wave nature

as wave by photoelectric effect.

so we can't say as matter because it has wave nature too.

Answer 2

Energy

Sun light is an energy, heat energy and light energy. And energy is not matter. It doesn't has a fixed volume or isn't made of particles as matters (solids, liquids, gases, etc.) do. Remember that energy at any form is not matter.