Final answer:
According to the Kinetic Molecular Theory, molecules in a solid are close together and their movement is slow, as they vibrate about fixed positions without moving from one place to another.
Step-by-step explanation:
The kinetic molecular theory (KMT) provides insight into the behavior and properties of the states of matter: solids, liquids, and gases. According to the KMT, the particles (atoms, molecules, or ions) in a solid are tightly packed together, often in a regular pattern, and they vibrate about fixed positions but do not generally move from one place to another. Their vibrational movement is relatively slow compared to the movement in gases. In contrast, in a liquid, particles move past each other but remain in constant contact, and in a gas, the particles move freely and independently at high speeds.
To answer the student's question directly: In a solid, according to the Kinetic Molecular Theory, the molecules are A. Close together. Additionally, the movement of molecules in a solid, according to KMT, is B. Slow.