A fossil you are radiometrically dating contains 4 micrograms of Uranium 235 and 4 micrograms of Lead 207. Uranium 235 decays to Lead 207; the half-life of Uranium 235 is 710 million years. How old is the fossil

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?