An aspirin is crushed into fine power why is it physical

Aradio signal from a gps satellite take only about 0.067 seconds to reach a gps reciever. if the speed of light is about 300,000km/s, then approximately how far away is the reciever from from the satellite?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?