Problem 196 - Introductory Chemistry Atoms First

Question

True or false: Photons of green light have a higher frequency than photons of blue light. True or false: Photons of blue light have a longer wavelength than photons of orange light.

Step-by-Step Solution

Answer

False; False

Step 1: Statement 1

Photons of green light have a higher frequency than photons of blue light. According to the order of colors in the visible light spectrum, green light comes after blue light (violet, indigo, blue, green, yellow, orange, and red). Since the frequency decreases as we move from violet to red, green light has a lower frequency than blue light. Therefore, this statement is False.

Step 2: Statement 2

Photons of blue light have a longer wavelength than photons of orange light. Once again, let's look at the order of colors in the visible light spectrum: violet, indigo, blue, green, yellow, orange, and red. Blue light comes before orange light, and we know that the wavelength increases as we move from violet to red. So, photons of blue light have a shorter wavelength than photons of orange light. This means the statement is also False.

Key Concepts

Photon Frequency

Frequency refers to how many wave peaks pass a particular point in a given time. For photons, specifically, it describes how often the electric and magnetic fields oscillate. Consider the visible spectrum—it ranges from violet to red. Photons towards the violet end have high frequencies, while photons on the red side have lower frequencies.

The energy of a photon is directly related to its frequency. You can calculate that energy using the equation \( E = h u \), where \( E \) is energy, \( h \) is Planck's constant, and \( u \) (nu) is the frequency.

It's important to note that higher frequencies mean higher energy. For example, blue and violet light have higher frequencies than green or red light.

Photon Wavelength

Photon wavelength is the distance between successive peaks of the wave. The wavelength helps determine the color of the photon in the visible light spectrum.

Wavelength and frequency are inversely related through the speed of light, \( c \): \( c = \lambda u \), where \( c \) is the speed of light, \( \lambda \) (lambda) is the wavelength, and \( u \) is the frequency.

Longer wavelengths mean lower frequencies. For instance, red light has a longer wavelength compared to a blue light, which means lower frequency and energy. Green light sits between blue and red in terms of wavelength.

Visible Light Spectrum

The visible light spectrum is a small part of the electromagnetic spectrum that our eyes can see. It ranges from approximately 380 nm to 750 nm in terms of wavelength.

• Violet light comes first and has the shortest wavelength and highest frequency.
• On the other end, red light has the longest wavelength and lowest frequency.

The visible spectrum includes all the colors that we can see, representing the visible part of the electromagnetic radiation. It's important to recognize how each color corresponds to a specific range of wavelengths and frequencies.

Color Order in Light Spectrum

When you look at a rainbow, the colors follow a specific order: violet, indigo, blue, green, yellow, orange, and red (often remembered by the acronym VIBGYOR).

This order is based on the photon's wavelength and frequency. As you move from violet to red, the wavelength increases, and the frequency decreases. This order is consistent in any visible spectrum representation, such as in prisms or rainbows. Understanding this order is essential for determining the relative frequency and wavelength of each color. For instance, knowing that blue light comes before green helps infer that blue has a higher frequency but a shorter wavelength than green.