Question

in a solid, the particles are held together tightly, and they do not move around freely. because the particles stay in about the same place, a solid generally keeps a certain shape. even though particles in a solid cannot move past one another, they are not completely still. the particles are constantly vibrating, or moving back and forth, in place. select all the true statements. particles in a solid are packed tightly. particles in a solid are completely still. particles in a solid have thermal energy.

Explanation:

The text states that particles in a solid are held together tightly, so "Particles in a solid are packed tightly" is true. It also says that particles in a solid are not completely still but are constantly vibrating, meaning they have thermal energy. So "Particles in a solid have thermal energy" is true. And it clearly contradicts that particles are completely still.

Answer:

Particles in a solid are packed tightly.
Particles in a solid have thermal energy.