The different states of matter – solid, liquid, gas, and plasma – are determined by the electromagnetic forces that keep atoms in position. Plasma is an exceptional state found in both the corona and cores of stars, as well as within lightning bolts.
The four states of matter are solid, liquid, gas, and plasma. It is crucial to distinguish plasma from blood plasma. In physics, plasma has been acknowledged as an ionized gas since the 1920s. The study of space plasma physics gained importance in the 1950s following the identification of the Van Allen radiation belts. Plasma is often witnessed during lightning.
Matter undergoes changes in its state due to varying physical conditions. When ice, consisting of hydrogen (H2) and oxygen (O) molecules arranged in a regular pattern, melts, it transitions to a new state, becoming liquid water. With further warming, the water molecules separate even more to form steam, which is a gas. In these common states, the positive charge carried by each atomic nucleus is balanced by the total charge of the orbiting electrons, resulting in a net charge of zero. Thus, each individual atom remains electrically neutral.
When heat is increased, the steam can undergo ionization, where an electron gains enough energy to break free from its atom. This leaves the atom with a positive charge and forms an ion. In sufficiently heated gases, ionization occurs multiple times, resulting in the creation of clouds containing free electrons and ions. However, not all atoms are necessarily ionized and some may remain unchanged without a charge. This mixture of ionized gas, which includes ions, electrons, and neutral atoms, is called plasma. For plasma to be classified as such, it must have enough charged particles for the gas to collectively respond to electric and magnetic fields.
Although plasma conducts electricity and contains both electrons and ions, it is overall electrically neutral on a macroscopic scale. The number of electrons and ions present in measurable amounts are equal. Electric and magnetic fields can influence the charged particles within the plasma, and the motion of these particles generates internal fields and electric currents. The intricate interactions involved in these processes make plasma a remarkable, captivating, and intricate form of matter.
Plasma can be found in various ordinary and unusual locations. Passing an electric current through neon gas generates plasma and light. Lightning, a huge electrical discharge in the atmosphere, forms a disorganized section of plasma. A portion of a comet’s flowing tail consists of plasma derived from gas ionized by sunlight and unknown methods. The Sun, a massive sphere measuring 1.5 million kilometers, is composed of plasma heated through nuclear fusion.
Scientists are studying plasma with practical applications in mind. Physicists are researching devices that generate and confine hot plasmas in magnetic fields in order to harness fusion energy on Earth. Plasma processes in space play a significant role in protecting Earth from cosmic radiation and the Sun’s influence on Earth primarily occurs through energy transfer in the ionized layers of the upper atmosphere. The properties of plasma will be crucial in the field of energy as capturing its energy could potentially surpass the power output of current nuclear power.