The shorter an elecrtomagnetic waves wavelength, the
a. faster is its speed
b. lower is its energy
c. smaller its amplitude
d. higher is its frequency

The higher is its frequency.

Explanation:Electromagnetic waves are types of waves that do not require a material medium for transmission. They include radio waves, microwaves, infra-red and gamma rays among others. Frequency refers to the number of complete oscillations in one second while wavelength is the distance between two successive crests or trough in a transverse wave.The frequency of electromagnetic waves varies inversely to the wavelength.Electromagnetic waves with higher frequencies such as x-rays and gamma rays have lower wavelengths. Those with higher wavelengths, on the other hand, such as microwaves and radio waves have lower frequencies.

The answer to that would be magnesium