What is the mass of a 4.00cm3 piece sodium chloride having a density of 2.16g/cm3

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3 -> a2cr(no3)3 + a3ag2so4

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?