when did plasma become a state of matter
Plasma (physics) Plasma (from Ancient Greek πλάσμα​, meaning 'moldable substance'[1]) is one of the four fundamental states of matter, and was first described by chemist Irving Langmuir[2] in the 1920s.[3] Unlike the other three states, solid, liquid, and gas, plasma does not exist freely on the Earth's surface under normal conditions. Plasma can only be artificially generated by heating or subjecting a neutral gas to a strong electromagnetic field to the point an ionised gaseous substance becomes increasingly electrically conductive, and long-range electromagnetic fields dominate the behavior of the matter.[4]
Atomic theory The idea that matter is made up of discrete units is a very old one, appearing in many ancient cultures such as Greece and India. The word "atom" was coined by the ancient Greek philosophers Leucippus and his pupil Democritus.[2][3] However, these ideas were founded in philosophical and theological reasoning rather than evidence and experimentation. Because of this, they could not convince everybody, so atomism was but one of a number of competing theories on the nature of matter. It was not until the 19th century that the idea was embraced and refined by scientists, as the blossoming science of chemistry produced discoveries that could easily be explained using the concept of atoms.