Question

phase changes
quiz complete
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the diagram below shows the different phase transitions that occur in matter.
which statement best describes the process that arrow 1 represents?
○ molecules are speeding up as boiling occurs.
○ molecules are slowing to a stop while freezing.
○ molecules are slowing down during condensation.
○ molecules are vibrating in stationary positions.

Explanation:

Step1: Identify arrow 1's process

Arrow 1 points from Liquid to Gas, which is boiling/vaporization.

Step2: Analyze molecular behavior in boiling

In boiling, liquid molecules gain energy, so they speed up and move into the gas phase.

Step3: Match to correct option

Only the first option describes speeding up during boiling, which matches the process of arrow 1.

Answer:

A. Molecules are speeding up as boiling occurs.