1. What happens when like charges come together?*

When like charges come together, they repel each other. For instance, when the north and south poles of a magnet come together, they push each other apart. The like poles in the magnet repel each other and unlike poles attract each other much. The same reaction occurs in like and unlike charges. Also, the repulsion acts along the line between the two charges.

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

hope this ! : )