Here's why:

* Gas: A gas consists of atoms or molecules that are not bound together. They move freely and collide with each other.

* Plasma: Plasma is a state of matter where electrons are stripped from atoms, creating a sea of free ions and electrons. This makes plasma electrically conductive and highly reactive.

The Sun is incredibly hot, with temperatures reaching millions of degrees Celsius. This extreme heat causes atoms to collide with such force that they lose their electrons, forming a plasma. So, while the Sun is composed of the same elements found in gas (primarily hydrogen and helium), its intense heat and ionization make it a plasma.