Which EM waves are invisible? (more than one correct answer)

Quasars are extremely distant celestial bodies. Investigators using a special telescope determined that a certain quasar was emitting waves with a frequency of 1.41 × 10⁹ Hz. An

electromagnetic spectrum is shown.

Which of the following is not in the electromagnetic spectrum?

Scientists observed a celestial object emitting a wavelength of 3 x 10^-10m. What type of telescope did the scientists have to use to view this?

Scientists observed a celestial object emitting a wavelength of 3 x 10³m. What type of telescope did the scientists have to use to view this?

The frequency of an x-ray is --

Scientists observed a celestial object emitting waves with a frequency of 1.41 x 10⁸ Hz. What type of telescope did the scientists have to use to view this object?

Scientists observed a celestial object emitting a wavelength of 3 x 10^-10m. What type of telescope did the scientists have to use to view this?

Quasars are extremely distant celestial bodies. Investigators using a special telescope determined that a certain quasar was emitting waves with a frequency of 1.41 x 10⁹ Hz. Using the electromagnetic spectrum provided, investigators were most likely using a telescope that detects -