Hi, What is the difference between Matter and Radiation?
Matter has mass, radiation doesn't.
Thus an atom is matter, but a photon is not.
Well, sometimes matter is described as radiation. For example there is Neutron Radiation. But UltrafastPED is pretty much correct. Matter has mass and takes up space, while radiation, which in this case just refers to photons, does not take up space nor do they have mass.
Separate names with a comma.