In this task, you are given a question and answer for that. The answer will fill in the blank or will complete the unfinished question. Your task is to provide an explanation based on the given question or fill-in-the-blank statement, and answer.

[EX Q]: Question: Given two equal measures of water by volume, which would be lighter 
 Answer: distilled water?
[EX A]: Water becomes more dense when it is colder and when it has more salt.

[EX Q]: Question: A cold object indicates its particles are going 
 Answer: slow
[EX A]: When particles move more slowly, temperature is lower and an object feels cooler.

[EX Q]: Question: When we get to the top of a mountain the air is 
 Answer: less dense
[EX A]:
At higher elevations, there is less air to press on a given area.