The answers to the questions are:
- (a) Wavelength in standard notation: \( 5.32e-05 \) meters
- (b) Diameter in scientific notation: \( 4.95 \times 10^{4} \) kilometers
Thus, the final answers are:
\[
\boxed{5.32e-05 \text{ meters}} \quad \text{and} \quad \boxed{4.95 \times 10^{4} \text{ kilometers}}
\]