Chapter 11ish Flashcards
Electromagnetic spectrum
- types of light organized by frequency
- visible light is in the middle
- the more left you go, the higher the wavelength (nm)
- the more right you go, the higher the frequency (Hz)
- ordered: radio, microwave, infrared, visible, ultraviolet, x ray, gamma ray
Absorbed light
The waves can be absorbed by the light, black objects are best at this
Transmitted light
Light passes through the object
Subcategories:
- transparent: all goes through
- translucent: all-most goes through but can scatter some rays
- opaque: none goes through
Reflected light
Light bounces off substance
Eg, mirror
Methods of energy transfer
- convection: L&G, ocean currents, air currents, no flow needed for energy transfer
- conduction: solid, electric stove element, flow needed for energy transfer
- radiation: no medium required, light travels through vacuum of space, no flow needed for energy transfer
Properties of light
- form of pure energy
- no mass
- travels in straight lines
- made of electromagnetic waves
- speed of light c= 3.0 * 10^8 m/s or 300,000 km/s
- light travels with electromagnetic waves, a wave with electrical and magnetic parts, doesnt require medium, travels at speed of light, most waves require a medium(physical substance that carries/transmits energy)
What is light
Excited electrons jump to higher energy levels, then fall back down, shedding excess energy that was absorbed by emitting light
Electrons fall back in different ways to produce different results/colours of light
Roygbiv
Red orange yellow green blue indigo violet
Red being highest wavelength(700nm)
Violet being lowest wavelength(400nm)
Incandescence
Production of light cuz of high temperature
Ex burning candle
A way of gaining energy & producing light
Electric discharge
Process of producing light by passing an electric current through a gas
Ex. Neon lights, lightning
A way of gaining energy & producing light
Phosphorescence
Produces light by absorption of UV light resulting in the emission of visible light over an extended period of time
Ex. Glow in the dark stickers
A way of gaining energy & producing light
Fluorescence
Immediate emmision of visible light as a result of the absorption of UV light
Ex. Fluorescent clothing that glows in the dark while being exposed to UV light
A way of gaining energy & producing light
Fluorescence + electric discharge
Ex. Energy saving fluorescent light bulbs
A way of gaining energy & producing light
Chemiluminescence
Direct production of light as the result of a chemical reaction with little or no heat produced
Ex. Glow sticks
A way of gaining energy & producing light
Bioluminescence
Production of light in living organisms as the result of a chemical reaction with little or no heat produced
Ex. Fireflies
A way of gaining energy & producing light
