Correct options:
- Blue light has a wavelength of 750 nm, the longest wavelength of visible light, and red has a wavelength of 500 nm. --> FALSE. It's actually the opposite: blue light has a wavelength of approx. 500 nm, while red has a wavelength of 750 nm, the longest wavelength of visible light.
- Light is electromagnetic radiation, a type of energy embodied in oscillating electric and magnetic fields. --> TRUE. Electromagntic radiation is a type of transverse waves, consisting of electric and magnetic fields oscillating perpendicularly to each other.
- The units of frequency are distance per second. --> FALSE. Frequency is measured in Hertz (Hz), which corresponds to 1/seconds (.
- The more closely spaced the waves, that is, the longer the wavelength, the more energy there is. --> FALSE. The energy of an electromagnetic wave is inversely proportional to the wavelength:
that means, the longer the wavelength, the less energy there is.
- Grass appears green because it reflects primarily the wavelength associated with green light and absorbs the others. --> TRUE. The color of the objects as we see them corresponds to the color they reflect, while all the other colors are absorbed by the object.
- Light in a vacuum travels at 3.00×108mph. --> FALSE. The units are wrong: the speed of light in a vacuum is .
- Electromagnetic radiation can be characterized by wavelength, amplitude, and frequency. --> TRUE. Wavelength is the distance between two consecutive crests, amplitude is the maximum displacement of the wave relative to the equilibrium position, frequency is the number of oscillations per second.
- The presence of a variety of wavelengths in white light is responsible for the way we perceive colors in objects. --> TRUE. White light consists of many different colors, and depending on which of them are absorbed/reflected by the objects, we perceive them in different ways.