How do balanced chemical equations show the conservation of mass?

Can someone me with 1 to 4 plz. fast

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.

Amap that uses a range of colors and shading to represent the elevation, depth, or landscape of specific features on earth is a/an map.