Answer:
Explanation:
They need a galvanic difference. Or saying that less technically, they need to have different electron attraction, so that one can collect electrons (oxidation/reduction) and flow current from the other. :)
If I drop my egg unprotected, then it will break.
Radio waves, Middle-C, and halitosis are not forms of light.
Answer:
A. the left half becomes neutral while the right half remains negatively charged
Explanation:
This is because wherever light strikes the photoconductor, it transforms from an insulator into a conductor. The charge will then migrate through it and leaves its surface. By exposing the left half of the photoconductor to light, you allow its local charge to leave and it becomes neutral.
The answer is d. Vacuum
Sound waves need a molecul to travel through. Gas , solid, annd liquid provide that medium.
But vacuum is just an empty space withour any moleculs in it.
Thats why in space, no one can hear you scream. Because it simply not physicsly possible