Electromagnetic waves.

Re cap!! Electromagnetic waves are transverse waves that are traveling at the speed of light and are associated with oscillating electric and magnetic fields.

#Electromagnetic waves transfer energy. The energy of electromagnetic waves is stored in the waves electric and magnetic field.

#The electromagnetic spectrum has a wide variety of applications and characteristics that cover a broad range of wavelengths and frequencies.

visible.

Radio.

Ultraviolet.

Infrared.

X-ray.

Extreme UV.

High-energy electromagnetic waves behave like particles. Sometimes, am electromagnetic waves frequency ( or wavelength) makes the wave behave more like a particle. This nation called wave-particle duality.

When thinking about electromagnetic waves as a stream of particles, it is useful to define a photon. What is a photon?

Low-energy photons tend to behave more like waves and higher photons behave more like particles. This distinction helps scientist design detectors and telescopes to distinguish different frequencies of radiation.

Radio waves seem completely different from visible light and gamma rays. They are produced and detected in very different ways. The electromagnetic spectrum.

The electromagnetic spectrum can be expressed in terms of wavelength, frequency or energy. Video!!

If you favorite the FM radio station 90.5 MHz (90.5x10^7). Infrared, visible and ultraviolet light are usually describes in terms of their wavelength. We see wave length 670 nm (6.70x10^- 7m) as red light. The shortest wavelengths radiation is generally describes in terms of the energy of one photon.

For example : the element cesiu,- 137 emits gamma rays with energy of 662 KeV ( 10^-13 J).

Radio Waves! Radio waves have the longest wavelengths in the spectrum. The wavelengths range in size from the diameter of a soccer ball to the length of a soccer filed and beyond.

Why is that? Because long wavelengths can easily travel around objects, they work well for transmitting information across long distances. Objects that are far away in deep space also emit radio waves. Because these waves can pass through earths atmosphere.

Microwaves. #The wavelength of microwaves range from 30 cm to 1 mm in length. #These waves are consider to be part of the radio spectrum and also regulates by the FCC. #Microwaves ovens use the longer- wavelength microwaves to cook your pop corn quickly.

They are also useful for transmitting information because they can penetrate mist, clouds, smoke and haze, Microwave towers through-out the world convey telephone calls and computer data from city to city. The shorter microwave length are used for radar. Radar works by sending out bursts of microwaves and detecting the reflections off of objects the waves hit.

Infrared. Infrared light lies between the microwave and the visible parts of the electromagnetic spectrum. There are two types if infrared. Near-infrared and far-infrared "Near infrared" light is closest in wavelength to visible light and "far infrared" is closer to the microwave region of the electromagnetic spectrum.

Far infrared waves are thermal. In other words, we experience this type of infrared radiation every day in the form of heat! The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared. The temperature-sensitive nerve endings in our skin can detect the difference between inside body temperature and outside skin temperature

Shorter, near infrared waves are not hot at all - in fact you cannot even feel them. These shorter wavelengths are the ones used by your TV's remote control.

Visible light. The wavelength that the human eye can see range from about 700 nm ( red light) to 400 nm ( violet light). This range is very small part of the electromagnetic spectrum! An incandescent light bulb gives off light- and-heat-from a glowing filament. In neon lights and lasers atoms emit light directly. Phosphors are one of the materials that emit light.

Ultraviolet. Ultraviolet light has wavelengths that are shorter than visible light, just beyond the violet. Our sun emits light throughout the spectrum, but the ultraviolet waves are the one responsible for the sun burns. This light can damage your retina. Various atmospheric gas such as ozone. Block most of the UV waves.

Ultraviolet light is often used to kill bacteria in city water suppliers or to sterilize equipments in hospitals.

X rays. X rays have very short wavelength. Wilhelm conard roentgen. A week later, he took an X-ray photograph of his wife's hand which clearly revealed her wedding ring and her bones. The photograph electrified the general public and aroused great scientific interest in the new form of radiation. Roentgen called it "X" to indicate it was an unknown type of radiation. The name stuck, although (over Roentgen's objections), many of his colleagues suggested calling them Roentgen rays. They are still occasionally referred to as Roentgen rays in German-speaking countries.

Gamma rays. The shortest wavelength electromagnetic waves are called gamma rays. As with X rays, gamma rays are usually described by their energy. The highest-energy gamma rays observed by scientist come from hottest region of the universe. Gamma rays can kill living cells. The universe is a huge generator of gamma rays.

By : Nehal Gamal. Thank you and good Luck next week garamb3z :P Ya nehal ya gamdaaaaaa(A)