The ampere is the unit of
a. charge
b. current
c. potential energy
d. distance between charged particles

Galileo was the first to notice that the moon has craters, valleys, and mountains. how might this have changed people's perception of the moon at the time?

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

Iron reacts with sulfur to form iron sulfide. if 60 grams of iron reacts with sulfur to produce 90 grams of iron sulfide, how much sulfur has been used in the chemical reaction?