PLEASE HELP ME QUICK When an iron nail is ground into powder, its mass .
a. stays the same
b. decreases
c. increases
d. cannot be determined

When paper turns yellow-brown upon exposure to sunlight, what type of change is likely taking place?

a. a physical change
b. a chemical change
c. neither a physical change nor a chemical change
d. both a physical change and a chemical change

The excretory system,need answers for all: )

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j

How do cfcs cause ozone depletion? how do cfcs cause ozone depletion? ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation breaks down cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks two oxygen atoms away from ozone, leaving behind a paired oxygen molecule. ultraviolet radiation creates cfcs, molecules containing chlorine. chlorine then breaks one oxygen atom away from ozone, leaving behind a paired oxygen molecule.