they can travel through a vacuum of outer space...When an electromagnetic wave impinges upon the atoms of a material, the energy of that wave is absorbed.
Answer: Which can travel through the vacuum of outer space. Mechanical waves,
Explanation: Unlike electromagnetic waves, require the presence of a material medium in order to transport their energy from one location to another. Electromagnetic waves are created by the vibration of an electric charge.
Because if we use too much coal we are wasting fossil fuels and burning coal hurts the environment so the alternative energy sources provide clean energy
