Nearly all personal electronic devices use a type of

memory known as Dynamic Random Access Memory

$($DRAM$).$ DRAM is where the $$working set$$ of instructions

and data for a processor are typically stored, and the ability

to pack an ever increasing number of bits on to a DRAM

chip at low cost has been critical to the continued growth in

computational capability.

At the most basic level, every bit of information that a

DRAM can store is associated with a capacitor. The amount

of charge stored on that capacitor $($and correspondingly, the

voltage across the capacitor$)$ sets whether a $1$ or a $0$ is stored in that location.

Let Cbit $=1\mathrm{.}8\backslash$times $10-14$ F $($a typical value$).$ The capacitor is initially charged to a voltage of $1\mathrm{.}2$ V to

store a $1.$ As long as the voltage remains above $0\mathrm{.}8$ V$,$ outside circuits can still recognize this

as a $1.$

In any real capacitor, there is always a charge $$leak$$ to cause it to eventually discharge. How

many electrons would have to leak from the negative plate to the positive plate of Cbit in order

for the $1$ memory state to be lost