An fron nallis made up of particles. What is true about the particles?

"They stay in place and vibrate" is true about the particles of iron.

Explanation:

The iron in solid state have tiny particles like atoms, molecules and ions which stay in their position and can only vibrate slightly as their arrangement is compact in nature which do not allow them to move all over the place due to strong force of attraction called as "inter-molecular attraction".

While iron in molten form, being semi-solid have more spaces between the particles, therefore they vibrate more than the particles in compact situation of solid state. And definitely the inter-molecular force of attraction is also weaker than in between actual solid iron particles.