Answer
The smallest structure that could be resolved would have a size of $1.23\times 10^{-11}~m$
Work Step by Step
We can find the wavelength of the electrons:
$\lambda = \frac{h}{p_e}$
$\lambda = \frac{h}{\sqrt{2~m_e~E_e}}$
$\lambda = \frac{6.626\times 10^{-34}~J~s}{\sqrt{(2)(9.1\times 10^{-31}~kg)(10,000~eV)(1.6\times 10^{-19}~J/eV)}}$
$\lambda = 1.23\times 10^{-11}~m$
The smallest structure that could be resolved would have a size of $1.23\times 10^{-11}~m$
