Infrared

Definition

Infrared is a type of electromagnetic radiation with wavelengths longer than those of visible light, but shorter than those of radio waves. It is a form of thermal radiation that is invisible to the human eye, but can be detected as heat by the skin and specialized sensors.

5 Must Know Facts For Your Next Test

1. Infrared radiation is often used in remote controls, night vision devices, and thermal imaging cameras due to its ability to detect heat signatures.
2. The infrared region of the electromagnetic spectrum is divided into three main categories: near-infrared, mid-infrared, and far-infrared, based on their wavelength ranges.
3. Infrared radiation is absorbed by greenhouse gases in the Earth's atmosphere, contributing to the greenhouse effect and global warming.
4. The energy of infrared photons is not high enough to ionize atoms or molecules, but it can be absorbed and converted into thermal energy, leading to an increase in the kinetic energy of the atoms or molecules.
5. Infrared radiation is used in various applications, such as heating, drying, and curing processes, as well as in medical and scientific research.

Review Questions

• Explain how infrared radiation is related to the concept of heat transfer in the context of 1.4 Heat Transfer, Specific Heat, and Calorimetry.
  • Infrared radiation is a form of thermal radiation, which is the emission of electromagnetic waves due to the thermal energy (heat) of an object. In the context of heat transfer, infrared radiation plays a crucial role in the transfer of heat between objects with different temperatures. When an object is heated, it emits infrared radiation, which can then be absorbed by other objects, causing them to warm up. This process of heat transfer via infrared radiation is an important concept in understanding topics such as specific heat and calorimetry, as the absorption and emission of infrared radiation can affect the temperature changes observed in these processes.
• Describe how the properties of infrared radiation are related to the concept of plane electromagnetic waves discussed in 16.2 Plane Electromagnetic Waves.
  • Infrared radiation is a type of electromagnetic radiation, and as such, it exhibits the properties of plane electromagnetic waves. Like other forms of electromagnetic radiation, infrared waves travel at the speed of light, have a specific wavelength and frequency, and can be described by the wave equation. The wavelength and frequency of infrared radiation determine its position within the electromagnetic spectrum, and these properties influence how it interacts with matter and propagates through different media, which is a key aspect of the study of plane electromagnetic waves.
• Analyze the role of infrared radiation within the broader context of the electromagnetic spectrum covered in 16.5 The Electromagnetic Spectrum.
  • Infrared radiation is a crucial component of the electromagnetic spectrum, which encompasses all forms of electromagnetic radiation, ranging from radio waves to gamma rays. Within this spectrum, infrared radiation occupies the region between the visible light and microwave bands, with wavelengths longer than those of visible light but shorter than those of radio waves. Understanding the placement of infrared radiation within the electromagnetic spectrum and its unique properties, such as its ability to be absorbed and emitted as thermal energy, is essential for comprehending its various applications and its impact on phenomena like the greenhouse effect and global warming, which are crucial aspects of the broader study of the electromagnetic spectrum.

Related terms

Electromagnetic Spectrum: The electromagnetic spectrum is the range of all possible frequencies and wavelengths of electromagnetic radiation, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Thermal Radiation: Thermal radiation is the emission of electromagnetic radiation from a surface or object due to the thermal energy (heat) of its atoms or molecules.

Blackbody Radiation: Blackbody radiation is the type of thermal radiation emitted by a perfect absorber and emitter of radiation, which is an idealized physical object that absorbs all electromagnetic radiation that falls on it, regardless of the angle or wavelength of the radiation.