3.10 understand that light is part of a continuous electromagnetic spectrum which includes radio, microwave, infrared, visible, ultraviolet, x-ray and gamma ray radiations and that all these waves travel at the same speed in free space

The electromagnetic spectrum consists of waves with different frequency and wavelength.There is a range of different types of electromagnetic radiation (energy that travels and spreads out as it goes). A section of the electromagnetic spectrum is visible light. The waves in the electromagnetic spectrum are continuous, which means that it has a constant amplitude and frequency.

Properties of the  Electromagnetic Spectrum:

• All waves transfer information and energy 
• All of the waves in the electromagnetic spectrum travel at the same speed when they are in a vacuum (3*10^8 m/s) or (300,000,000 m/s)
• All the waves in the electromagnetic spectrum are transverse waves