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.

[Q]: Question: Paul started at the base of a mountain and climbed to its peak. The sky was clear and the sun was beating down on him all day. However, he noticed there was a clear temperature difference between the surface's temperature and the temperature at the top of the mountain peak. Where would he feel more heat? 
 Answer: Surface
[A]: The surface is heated by the Sun and some of that heat radiates back into the air. This makes the temperature higher near the surface than at higher altitudes.


[Q]: Question: Will small pieces have more or less surface area than one large piece? 
 Answer: more
[A]: It would be hard to get a big chunk of chocolate to dissolve in your milk or hot water. Maybe you could make hot chocolate from some smaller pieces like chocolate chips, but it is much easier to add a powder to your milk. This is because the smaller the pieces are, the more surface area they have.


[Q]: Question: Ivan yells across a canyon in the morning when it is cold and again later in the afternoon when it is hot. During which time did his voice travel the fastest? 
 Answer: afternoon
[A]:
For a given medium such as air, sound has a slower speed at lower temperatures.