If an electromagnetic wave's frequency were increased by a factor of 2, then 0 its wavelength would increase by a factor of 4, and its speed through empty space would decrease by a factor of 2. 0 its wavelength would remain the same, and its speed through empty space would increase by a factor of 2. 0 its wavelength would decrease by a factor of 2, and its speed through empty space would remain the same. 0 its wavelength would decrease by a factor of 2, and its speed through empty space would increase by a factor of 4. 0 its wavelength would increase by a factor of 2, and its speed through empty space would remain the same