Electron Theory

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Presenting: Notes on Electron theory as interpreted by a liberal arts graduate who stopped studying science nearly 10 years ago. BOO!

All matter is made up of Molecules (smallest part of matter which can exist by itself).

  • Molecules are made up of Atoms
  • Each Atom is made up of Protons, Neutrons, and Electrons.
    • The Electron is the smallest lightest and negatively charged.
    • The Proton is 1800 times the mass of the electron and positively charged.
    • The Electron is attracted to the proton bcause opposites attract and cos the electron is smaller/lighter than proton.
    • Electrons repel electrons, protons repel protons, because the similar charges repels.

So Electrons move because there is a push (negative charge from electron) and a pull (positive charge from proton).

Atoms

Most atoms have a nucleus and this consists of all the protons of the atom and one or more neutrons.

For example:

  • Hydrogen(1) = single atom of Hydrogen has 1 proton and 1 electron orbiting it. the atomic weight is 1.
  • Helium(2) = single atom of Helium has 1 proton and 2 electrons orbiting.
  • Lithium(3), etc.....

All remaining electrons (always equal to number of nuclear protons) are orbiting around in different layers on top of the nucleus (in specific rings and paths).

  • 1st layer = max 2
  • 2nd layer = max 8
  • 3rd layer = max 18

The only atoms in which these rings are full are in the inert gaseous elements such as Helium, Neon, Argon, Krypton, Xenon, and Radon.

All other elements have one or more uncompleted rings of electrons.

Metals

Some electrons in the outer orbit of atoms such as in Copper or silver can be easily dislodged.

Electrons travel out into wide open spaces between atoms and molecules as "Free Electrons" (in converse those electrons which never can be dislodged as called "Bound Electrons")

It is these Free Electrons drifting around that makes electric currents possible!

Metals thusly are great. Plus they are malleable and you can make alloys out of them, which helps alter their properties favourably such as changing melting point or enhancing tensile strength.

  • Stainless Steel = Iron + small amt of carbon + chromium
  • Solder = Tin + Lead
  • Nichrome = Nickel + Chrome