Answer:
Nails rusting over time as they are exposed to oxygen
Explanation:
New substance with new property is formed
It have also changed the chemical property of the substance
It is difficult to reverse the change etc...
its the the first one u said
A transverse wave and a longitudinal wave.
Transverse:wave particles move at medium speed in perpendicular to the direction that the waves move
Longitudinal:wave particles move at medium speed in parallel to the direction that the wave moves
Hope this helps ^-^