Phase Change Quiz

Why does a solid keep its shape?

• Its molecules move freely in all directions

• Its molecules do not move at all

• Its molecules only move in place, not around each other

• Its molecules move away from each other

What allows a liquid to flow?

• Its molecules are locked in place

• Its molecules move around, not away from each other

• Its molecules move far apart

• Its molecules do not move at all

What happens to molecules in a gas?

• They stay in place

• They move away from each other

• They form a rigid shape

• They slow down and stop moving

What is a phase change?

• A change in how freely molecules can move

• A change in the molecules themselves

• A change in the shape of a solid

• A change that happens only in solids

What happens when energy is transferred to a substance?

• The molecules shrink

• The molecular attraction changes

• The molecules stop moving

• The molecules’ kinetic energy increases

What determines whether a phase change occurs?

• The shape of the molecules

• The interaction between kinetic energy and molecular attraction

• The color of the substance

• The weight of the molecules

What is temperature a measure of?

• The size of molecules

• The weight of molecules

• The number of molecules in a substance

• The average kinetic energy of molecules

What happens during freezing?

• The kinetic energy decreases, and the attraction pulls molecules together

• The molecules speed up and spread apart

• The kinetic energy increases enough to overcome attraction

• The molecules stop moving entirely

Why does a substance melt when heated?

• The molecules shrink

• The molecular attraction changes

• The kinetic energy increases enough to overcome the attraction

• The molecules disappear

How can a change at the molecular scale explain a change at the macroscale?

• Molecular movement affects how a substance appears and behaves

• Molecules do not affect what we see

• Molecules only change in solids

• Molecules have nothing to do with phase changes