A type of electromagnetic wave has wavelength 50 Å.
What is the speed of the wave in vacuum ?

Explanation

To find the speed of an electromagnetic wave in vacuum given its wavelength, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Wavelength**:
The wavelength (λ) is given as 50 Ångströms (Å). We need to convert this into meters for standard SI unit calculations.
\[
1 \, \text{Å} = 10^{-10} \, \text{m}
...