Each time the boy breathes, he exhales 0.5012 L of gas. How many moles of gas does he exhale?​

Which object forms when a supergiant runs out of fuel? a red giant a black hole a white dwarf a neutron star

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?

If 3 moles of a compound use 24 j of energy in a reaction, what is the a hreaction in j/mol?