Why can't I observe a voltage between two capacitor plates when only one of the plates is connected to a battery? Let's say I have a battery and a capacitor that is neutral. Now I connect the battery positive terminal to only one plate of the capacitor. From what I know, there is a potential difference between the terminal and the plate so there should be an electric field that causes some of the negative charges of the capacitor connected plate to move to the terminal (through a conducting wire) to reduce the potential difference to zero. This makes the connected capacitor plate to be positively charged which in turn causes the not connected plate to be negatively charged because there is an electric field between the plates that causes negative charges to gather in the not connected plate. Now after this happens I expect that there is a difference in potential between the plates of capacitor. But with a multimeter connected to the plates of the capacitor I can observe zero voltage. Why is that? What do I miss?
 A: There is no potential difference because the connection of the positive battery terminal simply causes a redistribution of charge on both plates, but no net charge on either plate. That would require current in a complete circuit involving the other battery terminal.
The free electrons of the connected plate move towards the surface of the plate connected to the positive battery terminal. That, in turn, induces movement of free electrons on the non connected plate towards the surface nearest the connected plate. But the end result is the net charge on the two plates remains zero for a potential difference of zero between the plates.
See FIG 1 below.
Hope this helps.

A: You have not mentioned anything about the negative terminal of the battery so I have not connected it to anything.
In the diagrams below the positions of charges and there distribution are illustrative as I do not know exactly how the positive charges will be distributed in diagram $\bf b$.

Diagram $\bf a$ shows the separation of charges on the terminals of the battery due to the electro-chemical process within the battery.
Diagram $\bf b$ shows the connection of the positive terminal of the battery to one plate of the capacitor.
Note that the bottom plate of the capacitor has to stay electrically neutral and not negatively charged as you have stated.
Diagram $\bf c$ shows a voltmeter connected across the plates of the capacitor which leads to the capacitor discharging (inner charges neutralise one another) and the reading on the voltmeter showing zero as in the final state (after more than five time constants $R_{\rm voltmeter}C_{\rm capacitor})$, effectively no current is passing through the voltmeter and so its reading is zero.
