Electromagnetic Spectrum (Basic science review)

1. Introduction
2. The electromagnetic spectrum
3. Ionizing Radition

Introduction

• Visible light is just a small part of the electromagnetic spectrum
• The waves of the electromagnetic spectrum are different only in their frequency.
• As the frequency goes up, the wavelength goes down.
• As the frequency goes up, the energy goes up.
• All electromagnetic radiation travels at the speed of light.

The electromagnetic spectrum

There are 7 different types of radiation recognized in the electromagnetic spectrum: radio waves, microwaves, infrared, visible light, ultraviolet, X rays, and gamma rays.

Fundamentally, the only difference in these types of radiation is the frequency. They are all electromagnetic radation and they all travel at the speed of light.

However, the spectrum is broken up into groups based on how the radiation is generated and how it is used or detected.

Ionizing Radition

• The energy of the photon is directly proportional to its frequency. (The higher the frequency, the higher the energy.)
• Above a certain frequency, the photon has enough energy to knock loose an electron out of a molecule. This ionizes the molecule and changes the bonds within the molecule.
• When ionizing radiation hits a DNA molecule, it may damage the DNA in a way that can lead to cancer.
• This frequency is in the ultraviolet range, so all electromagnetic radiation in the UV, X-ray, and gamma ray range can cause cancer.