The second one, the third one, and the fourth one
Yes. Look up Newton’s laws of physics. That should help
Answer:
The density of air goes down as you get higher with altitude.
Explanation:
Less air is pushing down on the molecules below it as you go up. This means that it is not as compacted, another word for which is dense.
Answer:
It changes into a liquid because when it gets heated up to a certain temperature, it reaches it's "boiling point", which is when it will start to transform into a liquid because the temperature is too hot for it to remain a solid.
Explanation:
Just think of when icicles melt because of the sun. The sun is heating them up and it gets too warm to the point that it liquidizes.
