TASK DEFINITION: In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
PROBLEM: Question: What are reversible physical changes in matter called? Answer: changes of state

SOLUTION: Changes of state are reversible physical changes in matter called.

PROBLEM: Question: How many neutrons do 99% of carbon atoms have? Answer: six

SOLUTION: Six many neutrons do 99% of carbon atoms have.

PROBLEM: Question: When gas particles collide, what kinds of collisions are these considered? Answer: elastic

SOLUTION:
When gas particles collide, these collisions are considered elastic.