Incandescence and Thermal Radiation

What is the minimum temperature at which virtually all substances start to glow visibly in the dark?

Chemiluminescence produces a significant amount of heat.

What is the process by which a substance absorbs energy and releases it slowly in the form of light?

The emission of light by a living organism is known as _______________.

What percentage of electricity is converted to light in an incandescent light bulb?

Match the following types of light emission with their descriptions:

Fluorescence is the emission of light by a substance that has absorbed light of a different wavelength.

What is the common application of fluorescence?

What is the primary advantage of CFL lighting compared to incandescent technology?

Scientists have a complete understanding of the phenomenon of triboluminescence.

What is the process by which LEDs emit light?

The tube in a CFL is lined with a coating of a fluorescent material, called the ____________________.

Match the following lighting technologies with their characteristics:

What is the color of the glow typically seen in triboluminescence?

Emission of light from a hot body due to its temperature
Substances start to glow visibly in the dark around 470 °C with a very dull red color
Incandescent light bulbs work by resisting the flow of electrons, heating the filament, and emitting visible radiation (5-10% of electricity) and infrared radiation (90-95% of electricity)

Production and emission of light by a living organism
Essentially chemiluminescence, but in living organisms
Found in marine vertebrates and invertebrates, microorganisms, and terrestrial animals

Process of energy absorption and slow release in the form of light
Causes "glow-in-the-dark" effect
Energy is absorbed by exposure to ultraviolet light and stored for a longer time

Emission of visible light by a substance that has absorbed light of a different wavelength
Release of energy is almost immediate
Occurs in fluorescent tubes, where ultraviolet light is absorbed and re-emitted as visible light

Electronic light source that works by electroluminescence
Electrons recombine with holes to release energy in the form of light
Advantages: lower energy consumption, longer lifetime, improved robustness, smaller size, faster switching, durability, and reliability

Optical phenomenon where light is generated when crystals are broken or deformed
Scientists do not fully understand the mechanism, but it is believed to involve the separation of electric charges and recombination sparks
Appears as a blueish, blueish-greenish, or white glow