Limitations of chemical reaction​

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Which element would mostly likely have an electron affinity measuring closest to zero

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.