To find out how many times smaller \( 5 \times 10^{-7} \) is than \( 8.5 \times 10^{-4} \), you can divide the two numbers:
\[ \text{Factor} = \frac{8.5 \times 10^{-4}}{5 \times 10^{-7}} \]
First, simplify the exponents:
\[ = \frac{8.5}{5} \times \frac{10^{-4}}{10^{-7}} = \frac{8.5}{5} \times 10^{-4 + 7} = \frac{8.5}{5} \times 10^{3} \]
Now, calculate \( \frac{8.5}{5} \):
\[ \frac{8.5}{5} = 1.7 \]
Multiply by \( 10^{3} \):
\[ 1.7 \times 10^{3} = 1,700 \]
Thus, \( 5 \times 10^{-7} \) is \( 1,700 \) times smaller than \( 8.5 \times 10^{-4} \).
The correct answer is 1,700.