A25 pf parallel-plate capacitor with an air gap between the plates is connected to a 100 v battery. a teflon slab is then inserted between the plates, and completely fills the gap. what is the change in the charge on the positive plate when the teflon is inserted?

5.3 nC

Explanation:

The initial charge stored on the capacitor is given by:

(1)

where

is the capacitance of the capacitor

is the potential difference across the capacitor

Substituting numbers into the equation, we have

When the Teflon slab is inserted between the plates, the capacitance of the capacitor is increased as follows:

where k=2.1 is the dielectric constant of the Teflon. Since the voltage V remains constant, this means that the new charge stored by the capacitor (1) will be

and so

a.   mass number from atomic number