Light and sound aren't matter because Photons have no mass.
Animals communicate using signals, which can include visual; auditory, or sound-based; chemical, involving pheromones; or tactile, touch-based, cues
Answer:
C. 10
Explanation:
So wr for protons is 2 and wr for alpha particles is 20. In these terms, alpha particles cause ten times more damage then protons.
