Which of the following elements is the most reactive?
a. at
b. cl
c. br
d. i
how can you tell if it's reactive? what do you look at?

What do electromagnetic waves carry? how are they produced through which media can they move? where do they transfer energy? what do they not transfer? what do mechanical waves carry? how are they produced? through which media can they move? where do they transfer energy? what do they not transfer?