To compare the two values \( 5 \times 10^{-11} \) and \( 3 \times 10^{-11} \), we can examine the coefficients because they are both multiplied by the same power of ten.
- For \( 5 \times 10^{-11} \), the coefficient is 5.
- For \( 3 \times 10^{-11} \), the coefficient is 3.
Since 5 is greater than 3, we write:
\[ 5 \times 10^{-11} > 3 \times 10^{-11} \]
Thus, the correct symbol to put in the blank is:
So the complete statement is:
\( 5 \times 10^{-11} > 3 \times 10^{-11} \)