Acee 2

Are very difficult to recycle because they are composed of two or more phases that are normally intermixed on a fine scale.

Visible light lies within a very narrow region of the spectrum, with wavelengths ranging between about

Planck's Constant. ?

Some materials are capable of absorbing energy and then reemitting visible light in a phenomenon called

Electromagnetic radiation may be considered to be composed of photons—groups or packets of energy that are quantized, that is, they can have only specific values of energy.

Is expressed in hertz (Hz), where 1 Hz = 1 cycle per second

Is proportional to the frequency of the radiation and inversely proportional to its wavelength.

Materials that are capable of transmitting light with relatively little absorption and reflection; light is transmitted through the material with very little absorption and reflection.

Light is transmitted diffusely; there is some scattering within the interior of the material. Materials on which light is transmitted diffusely; that is, light is scattered within the interior, to the degree that objects are not clearly distinguishable

Virtually all light is scattered or reflected such that none is transmitted through the material. Materials that are capable of transmitting light with relatively little absorption and reflection.

The electric field component of a light wave induces a shift of the electron cloud around an atom relative to its nucleus

Two consequences of electronic polarization

€� Metals appear opaque as a result of the absorption and then reemission of light radiation within a thin outer surface layer.

Absorption occurs via the excitation of electrons from occupied energy states to unoccupied ones above the Fermi energy level

When light passes from one transparent medium to another having a different index of refraction, some of it is reflected at the interface.

Light that is transmitted into the interior of transparent materials experiences a decrease in velocity, and, as a result,

Pure nonmetallic materials are either intrinsically transparent or opaque. Some light absorption occurs in even transparent materials as a consequence of electronic polarization.

Light which travels through a sample without being absorbed or reflected, but includes light which is scattered forward.

Absorption of energy by atoms followed by immediate emission of electromagnetic radiation; When light is reemitted in less than a second after excitation,

For longer reemission times, absorption of energy by atoms followed by delayed emission of electromagnetic radiation is a slow process that continues even after the source is removed

LASER meaning

Generate coherent light through electron transitions initiated by an external stimulus

A solid-state laser that uses a synthetic ruby crystal as its gain medium

Is a device that causes laser oscillation by flowing an electric current to semiconductor.

Which protects the core and cladding from damage

A _________ through which the pulses of light propagate

Provides for total internal reflection and containment of the light beam within the core

Is the phenomenon whereby light is emitted as a result of electron–hole recombination events that are induced in a forward-biased diode

Is the phenomenon whereby the electrical conductivity of some semiconductors may be enhanced by photo-induced electron transitions, whereby additional free electrons and holes are generated.

€� Magnetic flux density and magnetic field strength are proportional to one another.

Diamagnetic and paramagnetic materials are considered nonmagnetic because the magnetizations are relatively small and persist only while an applied field is present.

Foollowing are ferromagnetic materials except

Below its Curie temperature, a ferromagnetic or ferrimagnetic material is composed of domains—small-volume regions wherein all net dipole moments are mutually aligned and the magnetization is saturated

Some ceramics also exhibit a permanent magnetization,