Which of these is an example of a physical change?
A) iron melting
B) steel rusting
C) paper burning
D) wood decaying

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.

Arectangle has a diagonal 20 inches long that forms angles of 60 and 30 with the sides. find the perimeter of the rectangle. for geometry

Ahelium balloon contains 16.9 l of helium at stp. how many atoms of helium are in the balloon