Question

Which type of electromagnetic radiation has the shortest wavelength? (a) radio waves (b) microwaves (c) infrared (d) ultraviolet

Short answer

Ultraviolet radiation has the shortest wavelength among the provided options.

Step-by-step solution

Understand the Electromagnetic Spectrum

Recognize that the electromagnetic spectrum is arranged based on wavelengths and frequencies. Shorter wavelengths correspond to higher frequencies and energy. The types of electromagnetic radiation from longest wavelength to shortest are: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Identify the Shortest Wavelength Option

From the provided options, identify which type of electromagnetic radiation is closest to the higher frequency, higher energy end of the electromagnetic spectrum. The correct order from longest to shortest wavelength within the options given is: (a) radio waves, (b) microwaves, (c) infrared, (d) ultraviolet.

Choose the Correct Answer

Based on the knowledge of the electromagnetic spectrum, ultraviolet radiation has a shorter wavelength than radio waves, microwaves, and infrared. Therefore, (d) ultraviolet is the type of electromagnetic radiation with the shortest wavelength among the options given.

Key concepts

Wavelength and Frequency

Understanding the relationship between wavelength and frequency is crucial when studying the electromagnetic spectrum. In simple terms, the wavelength is the distance between successive crests of a wave, often measured in meters. Frequency, on the other hand, is the number of waves that pass a point in a second and is measured in hertz (Hz). These two properties of waves are inversely proportional to each other, which means that as the wavelength decreases, the frequency increases, and vice versa. This is important because the energy carried by electromagnetic radiation is directly related to its frequency: the higher the frequency, the higher the energy.

This inverse relationship can be mathematically expressed by the equation: \( c = \lambda \times f \), where \( c \) is the speed of light in a vacuum, \( \lambda \) is the wavelength, and \( f \) is the frequency. Since the speed of light is constant (\( c \approx 3.0 \times 10^8 \) meters per second), any increase in frequency (\( f \) must result in a decrease in wavelength (\( \lambda \) and vice versa. When comparing types of electromagnetic radiation, remember this principle to easily determine which has shorter or longer wavelengths based on their frequency.

Types of Electromagnetic Radiation

Electromagnetic radiation encompasses a broad range of wavelengths and frequencies, each corresponding to a different type of radiation. This is commonly known as the electromagnetic spectrum. The types of electromagnetic radiation include, in order of increasing frequency and decreasing wavelength: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Each type of radiation has its unique applications and effects on matter.

• Radio waves are used for communication such as in radio and television broadcasts.
• Microwaves are used for cooking food and in radar technology.
• Infrared is used in remote controls, night-vision equipment, and to study the thermal properties of objects.
• Visible light is the only part of the spectrum we can see with our eyes, enabling us to perceive the world in color.
• Ultraviolet radiation has sanitizing properties and is used in medical therapy but can also be harmful to skin and eyes.
• X-rays are used in medical imaging to view the inside of the human body.
• Gamma rays are used to treat cancer and sterilize medical equipment due to their high energy.

Understanding these types helps us harness the potentials of electromagnetic radiation and protect ourselves from its dangers.

Ultraviolet Radiation

Ultraviolet (UV) radiation lies between visible light and X-rays in the electromagnetic spectrum, with wavelengths typically between 10 and 400 nanometers. Because of its position in the spectrum, UV radiation has higher energy than visible light and can bring about chemical reactions when absorbed by materials. There are three main types of UV radiation based on their wavelength: UVA, UVB, and UVC, with UVC having the shortest wavelength and thus the highest energy.

Biological Effects of UV Radiation

UV radiation, while beneficial in moderation such as in the production of vitamin D in the skin, can also be harmful. Prolonged exposure to UVB, for example, can lead to skin damage, sunburn, and an increased risk of skin cancer. UVC is mostly absorbed by the Earth's ozone layer, but it can be artificially produced and is used to disinfect air and water due to its germicidal properties.

UV radiation also plays a crucial role in astronomy, where it helps astronomers gather information about the high-energy processes happening in the universe. Protective measures such as wearing sunscreen and limiting direct sun exposure during peak hours are widely advised to minimize the adverse effects of ultraviolet radiation.