Charge ion for Mg is 2+
While 2+ is represents two electrons that had been released. It donors two electrons to oxide ions as oxide ions are 2-. 2- is represents as electron acceptor for two electrons. At the end, the empirical formula for this reaction is Mg2O2
Reflection. The sound waves bounced off of the walls and it came back to you.
In hair dryer,
A part of electrical energy is converted to Heat energy and a major part of it is converted to mechanical energy in the form of rotation of the blades at high speed.