Karan Thakulla
B.Sc. Fourth Semester
Kailali Multiple Campus, Dhangadhi, Kailali, Nepal
We are very much familiar with three states of matter i.e. solid, liquid, and gas. When solid is heated then it converts into liquid and liquid gets converted into gas and at last when gas is heated further, it takes new states of matter which is called plasma. Plasma is also called ionized gas because plasma is formed by the ionization of gas.
Here question arises that what happens when we increase the temperature of gas from thousands degree Celsius to billion degree Celsius, will it just remains as a gas? Answer is No. Up to the temperature of 1000 degree Celsius it is in the form of gas but beyond this temperature, it will changes to a new state of matter called plasma, which is also called as fourth state of matter.
Plasma was discovered by Sir William Crooks in the laboratory first time he called it “radiant energy”. After systematic Irving Langmuir and his colleagues introduced the term “plasma” in 1920.
How is plasma formed?
To get better understanding of the plasma, let us consider some atoms of neon gas and we are interested to remove the electrons from these atoms. To remove electrons we need to provide very high amount of heat energy to these atoms. Once the atoms absorb heat energy, electrons will be removed from them. As a result of this, the neon atom becomes positive ion. Now the gas is the mixture of negatively charged electrons and positive ions. This ionized state of matter is called plasma.
We can define plasma as a super heated matter in which electrons are taken out from the atoms forming an ionized gas. It is made up of positive charged ions and free electrons.
Why is it important to know?
In the universe more than 99% of the visible matter is in the form of plasma state. Plasma is found in the stars including our own sun as well as in the vast region of space between the galaxies. Plasma is of two types viz. natural and artificial plasma. Natural plasma are found in stars, nebulas, interstellar spaces and so on. Whereas artificial plasma can be produced in the lab. The properties and behaviour and properties plasma is different from that of solid, liquid and gas. There is huge difference between gaseous state and plasma state. For example, electric and magnetic field does not affect the motion of gas molecules whereas they affect the motion of plasma particles. As plasma consists of charged particles, electric and magnetic field affects it.
Plasma has numerous applications in our today’s world. Plasma is used for making computer chips, rocket propulsion, cleaning the environment, destroying biological hazards, and in medical fields. Therefore, it is a subject of great interest for many people.