Lava is rock that has undergone a physical change and has liquified. What is known about this change? The lava gained mass. The lava was burned into smoke. The lava can cool back into...

Lava is rock that has undergone a physical change and has liquified. What is known about this change?

The lava gained mass.
The lava was burned into smoke.
The lava can cool back into rock.
The lava lost mass.
Expert Answers
sharikendrick eNotes educator| Certified Educator

When solid rock changes into its liquid lava state, a physical change has occurred. In a physical change, the particles of a substance rearrange, but do not change into different particles.

As heat energy is applied to a solid rock, the forces holding the particles in the rock together are disrupted and the solid rock transitions into a liquid lava state. In the liquid lava state, the particles are able to move around and slide past one another. When heat energy is removed from the liquid lava, the particles become more strongly attracted to one another and the substance transitions back into the solid rock state. Therefore, the correct answer is "The lava can cool back into rock."

According to the Law of Conservation of Mass, mass cannot be created or destroyed. Therefore, when solid rock changes into liquid rock, the mass of the rock does not change. The first and fourth answer choices are incorrect, because there cannot be any gain or loss of mass when the solid rock changes to liquid lava.

Burning of lava is an example of a chemical change. In a chemical change, the particles of a substance change into different particles. 

 

 

Access hundreds of thousands of answers with a free trial.

Start Free Trial
Ask a Question