Phase Changes

How are molecules typically arranged in a solid substance?

• Randomly dispersed with no fixed positions.

• Loosely packed and able to slide past each other.

• Neatly lined up and carefully arranged in a fixed structure.

• Constantly moving freely throughout the entire volume.

What happens to the movement of molecules when a solid melts into a liquid?

• They stop moving completely.

• They become more organized and slow down.

• They start moving faster and break free from their rigid structure.

• They remain in fixed positions but vibrate more intensely.

Which statement best describes the molecular arrangement and movement in a liquid?

• Molecules are tightly packed and vibrate in fixed positions.

• Molecules are disorganized and move around freely, but remain close together.

• Molecules are widely spaced and move randomly at high speeds.

• Molecules form a crystalline lattice and exhibit minimal motion.

What happens to molecules as a liquid transitions into a gas?

• They slow down and become more organized.

• They move faster and escape the liquid phase.

• They remain stationary but change their shape.

• They become more densely packed.

What is the process called when a gas loses heat and its molecules slow down to form a liquid?

• Vaporization

• Melting

• Freezing

• Condensation

When a liquid freezes into a solid, what change occurs in its molecular arrangement and motion?

• Molecules move faster and become less organized.

• Molecules become more disorganized and spread out.

• Molecules slow down and form a very organized structure.

• Molecules increase their kinetic energy.

How does the addition or removal of heat affect the movement of molecules in a substance?

• Adding heat makes molecules move slower, while removing heat makes them move faster.

• Adding heat makes molecules move faster, while removing heat makes them move slower.

• Heat only affects the arrangement of molecules, not their speed.

• Molecular movement is independent of heat.