What is the energy of a photon with frequency 4.40*10^14 S^-1? a) 2.92*10^-19 J
b) 6.61*10^-19 J
c) 7.85*10^-19 J
d) 3.05*10^-19 J
e) none of the above

Drug abuse will not lead to physical and psychological dependence. true or false ?

The excretory system, need answers for all: )

Most materials are not magnetic because their magnetism has worn off. their magnetic domains are arranged randomly. they lack magnetic fields. earth’s heat has destroyed their magnetism.