What is happening in terms of matter and energy, while wood burns?

The law of conservation of mass states that matter cannot be created or destroyed in a chemical reaction. For example, when wood burns, the mass of the soot, ashes, and gases, equals the original mass of the charcoal and the oxygen when it first reacted. So the mass of the product equals the mass of the reactant

b.transmitters send radio waves, and receivers capture radio waves.