Which statement best describes plasma?

Which statement best describes plasma?

• A. A solid object with bound electrons
• B. A liquid metal
• C. A state of matter where electrons are free from nuclei; protons and electrons move independently
• D. A gas that is always cold

Answer: (C)

Plasma is a state of matter in which atoms are ionized, so electrons are not bound to nuclei and move freely. In this mix, you have free electrons and positively charged ions that can move and interact with each other and with electromagnetic fields. These free charges give plasma its distinctive behaviors, like electrical conductivity and responsiveness to magnetic fields, and it can emit light as electrons recombine with ions. The description that best fits this is the one stating that electrons are free from nuclei and that the charged particles move independently, capturing the idea of ionization and free charges that define plasma. The other options describe solids, liquids, or gases in ways that don’t involve ionization and free charges, so they don’t fit plasmas.

Plasma is a state of matter in which atoms are ionized, so electrons are not bound to nuclei and move freely. In this mix, you have free electrons and positively charged ions that can move and interact with each other and with electromagnetic fields. These free charges give plasma its distinctive behaviors, like electrical conductivity and responsiveness to magnetic fields, and it can emit light as electrons recombine with ions. The description that best fits this is the one stating that electrons are free from nuclei and that the charged particles move independently, capturing the idea of ionization and free charges that define plasma. The other options describe solids, liquids, or gases in ways that don’t involve ionization and free charges, so they don’t fit plasmas.