A physical substance through which energy can be transferred
Radiation
A method of energy transmission that does not require a medium
Wavelength
The distance from one crest to the next
Electromagnetic waves carry both electric and magnetic parts
In a vacuum the wave travels at the speed of light, 3.00 * 10 ^ 8 m / s
Electromagnetic wave types
Radio waves
Microwaves
Visible light
X-rays
Gamma rays
Classification of waves
Classification of ways by their energy levels
Visible light is a small range of the entire spectrum
Visible light
Electromagnetic waves that the human eye detects
Colors of visible light
Red
Orange
Yellow
Green
Blue
Indigo
Violet
White light
Made up of all the colors of light in the visible spectrum
Light production
1. Atoms within a material absorb some form of energy
2. Electrons become excited and jump to a higher energy level
3. When the electron returns to the original energy level they release energy in the form of a photon (light)
Sources of light
Sun
Incandescence
Electric discharge
Fluorescence
Phosphorescence
Chemiluminescence
Bioluminescence
Triboluminescence
LED lights
Incandescence
When materials such as metals are heated to a high temperature they begin to glow, starting red and transitioning to orange, yellow, white, and then bluish white
Electric discharge
When an electrical current passes through a gas, light is produced
Phosphorescence
Phosphorusabsorb light at a high energy and release visible light at a lower energy
Fluorescence
When an object absorbs ultraviolet light and immediately releases the energy as visible light
Chemiluminescence
A chemical reaction can result in the production of light/energy, typically with no heat produced
Bioluminescence
Chemiluminescence occurring in a living organism
Triboluminescence
When certain types of crystals are scraped or banged together, sparks are produced
Light emitting diodes (LEDs)
A type of electrical switch made from semiconductor materials such as silicon, that only flow in one direction
Light travels in a straight line
Incident light
Light emitted from a source
Virtual image
An image formed by light coming from an apparent light source, where the image is formed by rays that do not come from the location of the image
Concave mirror
Reflection is from the inner surface of the spherical section
Convex mirror
Reflection is from the outer surface of the spherical section
Physical change
Reversible change that does not create a new substance
Chemical change
Irreversible change that creates at least one new substance
Physical property
Something that can be observed without a new object forming
Qualitative property
Physical property that involves the five senses
Quantitative property
Physical property that involves numbers
Chemical property
Description of how two substances interact
Diatomic elements
Two of the same elements combined
Proton
Positively charged and in the nucleus
Neutron
Neutral and in the nucleus
Electron
Negative in the orbit
In an atom the number of protons and neutrons are the same