# Lesson 4: Solid, Liquid, Gas: What's the Difference?

## Wrapping Up

### Conclusion

In this lesson, you have looked more closely at the differences among the states of matter. As the unit progresses, keep in mind that each of the elements has unique characteristics that influence which state the molecules are usually found in. This lesson was designed to help you to make connections between the classical states of matter, conditions necessary for the states to occur, and what each state of matter might look like at the atomic level. In considering the basic illustrations, remember that all states of matter, regardless of which element you are considering, have the same basic characteristics.

### Questions to Discuss

• Compare gas and liquid states of matter. What are two major differences? (Gas volumes can continue to expand; liquid volumes will remain fairly constant. When comparing the concentration of gas particles compared with liquid particles in an equal-sized container, the concentration of liquid particles is much higher.)
• Compare gas and solid states of matter. What are two major differences? (Gas volumes can continue to expand; solid volumes remain constant regardless of container; the shape of gases can change based on container; solid shapes are constant; gas molecules move freely and solid molecules are fixed in their positions.)
• Compare liquid and solid states of matter. What are two major differences? (Solid volumes remain constant regardless of container; the shape of liquids can change based on container. Solid shapes are constant; liquid particles move freely, but solid molecules are fixed in their positions.)
• Challenging Question: What causes solids to transition to liquids and liquids to transition to gases? (Chemical bonds between particles of matter influence the state of matter. Strong bonds link particles together. The bonds that hold particles together are influenced by the strength of the bond and the amount of energy present in the surroundings. Higher amounts of energy begin to weaken bonds. The more energy present, the greater the likelihood of a transition into a different state of matter.)

### Things to Review

• Solids have fixed shapes, and the particles of solids do not freely move.
• Liquids have flexible shapes based on the shape of their containers; liquid particles move by each other.
• Gases have flexible shapes; gas particles move freely by each other; the volume of gases can continually increase.