Explanation:
The wavelength of x rays are between 1 and 10 nanometers.
1 nm = 10⁻⁹ m
The greatest wavelength is 10 nm.
10 nm = 10 × 10⁻⁹ m
= 10⁻⁸ m
Here, (-8) is the exponent of 10.
Hence, the wavelength of the greatest wavelength of x-ray is 10⁻⁸ m.