Help pls. Are they a pure substance or mixture?

Using the periodic table, complete the table to describe each atom. type in your answers

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?

Describe the forces both attractive and repulsive that occur as two atoms move closer together.