អង្គធាតុ គឺជាអ្វីៗដែ​លយើងអាចមើលឃើញផ្ទាល់នឹងភ្នែកទទេវាអាចជាវត្ថុរឹង​,រាវ​ ឬឧស្ម័ន

អង្គធាតុ
Matter is usually classified into three classical states of matter, with plasma sometimes added as a fourth state for scientific purposes. From left to right: grains of refined sucrose (a solid), water (a liquid), depiction of particles in a gas, and a plasma globe (plasma).