Light, microwaves, x-rays, and TV and radio transmissions are all kinds of electromagnetic waves.
same kind of wavy disturbance that repeats itself over a distance called the wavelength. .
The wave, or "disturbance," is in an invisible thing called the electric force field. .
To understand electric forces, we have to learn something about charged particles like .
electrons and protons. Without these charged particles, there can be no electric .
force fields and thus no electromagnetic waves. .
What are electrons and protons?.
An electron is a particle with negative charge and not much mass. The positively charged .
proton exerts an invisible, attractive force on the electron -- an electric force.
the electric force is like an invisible spring, but as the charges move farther apart, .
a weaker spring pulls them together.An electron's motion depends on both the force on the .
electron and its velocity, which are often in different directions. .
What is a Force field?.
In physics, a force field is a way to picture the effects that electric charges .
have on one another. Instead of talking about the force a positive (+) charge.
exerts on an electron, we can say the charge creates a force "field" in the empty space around it. An electron put down at any place in this force field is pulled .
towards the + charge; a positive charge set down at the same place is pushed away.
What are Spectral Lines?.
At the end of 19th century, physicists knew there were electrons inside atoms, .
and that the wiggling of these electrons gave off light and other electromagnetic radiation.
But there was still a curious mystery to solve. Physicists would heat up different .
elements until they glowed, and then direct the light through a prism. .
They found bright lines of certain colors. Actually, "color" isn't the right term, because only some of the lines were visible.
Each type of atom gives off a unique set of colors. The colored lines (or Spectral Lines) .
