The effects of fluctuating temperature on the rocks that causes the rock to break apart from the massive rock are known as Physical weathering. Freeze-thaw (occurs due to the water leakage into clefts, freezing and extending, and finally separating the rock) and Exfoliation (occurs as clefts form equal to the surface of the land a result of the conversion in pressure through uplift and abrasion) are the two chief varieties of physical weathering.
Thus, Exfoliation is the separation of consecutive thin crusts from huge rock such as basalt or granite.
"Electrons are the "material" of the charge that is flowing. Therefore, current can never cause a metal object to become positively or negatively charged, because the net number of electrons in the metal object will never change due to current flow."