Question

1. looking at the picture to the right, was energy added or removed from point a to point b?
2. which of the 5 changes in states of matter we discussed in class is taking place in the picture above in question 8?

Explanation:

Step1: Analyze particle arrangement change

In the picture, from Point A (particles in an orderly - arranged solid - like structure) to Point B (particles more spread out and moving freely like a liquid or gas), energy is needed to break the intermolecular forces holding the particles in place in the solid. So energy is added.

Step2: Identify state - change type

The five changes in states of matter are melting (solid to liquid), freezing (liquid to solid), evaporation (liquid to gas), condensation (gas to liquid), and sublimation (solid to gas). Here, going from a more ordered (solid - like) to a less - ordered state is melting.

Answer:

1. Energy was added.
2. Melting.