As more and more energy is added to the atoms of a solid plastic, the plastic will first change into which state?

• A. a gas
• B. a plasma
• C. an ionic solid
• D. a liquid

Answer: (D)

Verified step by step guidance

1. Understand the states of matter: solids, liquids, gases, and plasma, and how energy affects transitions between these states.
2. Recall that when energy (usually in the form of heat) is added to a solid, its particles gain kinetic energy and begin to vibrate more vigorously.
3. Recognize that as the energy increases, the solid reaches its melting point, where it changes from a solid to a liquid state.
4. Note that the transition from solid to liquid is called melting, and this occurs before the substance can become a gas or plasma.
5. Therefore, the first state change for a solid plastic upon adding energy is to become a liquid.