Answer:
music amplifier or a loudspeaker
Explanation:
A music amplifier or a loudspeaker are a few devices that convert electrical energy into sound energy.
As it is a well known fact that energy can neither be created nor be destroyed it can only change from one form to the other. As here it is changing from electrical to sound.
First off chlorine is not a metal so you can ignore that one.
Sodium and Rubidium are in group 1 of the periodic table and Magnesium is in group 2.
Group one metals are more reactive than group two because it is harder for the group two metals to lose their 2 valence (outer most) electrons.
As you go down group 1 there is an increase in the reactivity this is because as you go down there is an increase in the atomic radius which leads to more shielding. This weakens the electrostatic forces of attraction making it easier to lose the outermost electrons, therefore they are more reactive.
(E) ionic aluminum fluoride (AlF3)
If I’m right this should be the answer
The difference between the two is that the values in discontinuous variation are fixed, while the values in continuous variation can be changed. :)