Answer: Wavelength increases and frequency decreases.
Explanation:
Electromagnetic spectrum is formed of radiations varying in frequency and wavelength like gamma rays, radio waves, UV rays, visible, and microwaves. We know that wavelength is proportional to frequency. Since the wavelength is proportional to frequency, the wavelength increases.
A volcano erupts quietly if it's magma is low on silica. Low silica magma will be very thin, runny, and will flow easily, so the gases in the magma will bubble out gently. Hope this helps!:)