Neutral atoms always have equal numbers of

Which best explains why an iceberg floats?

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

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?