Select the correct answer from each drop-down menu. An atom has 9 electrons and 9 protons at the start. If it loses 2 electrons, the net charge on the atom will be . If the atom instead gains 4 electrons, the net charge will be .

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.