Chemistry

Chemistry

1. Atoms and Elements

   • Atoms are the buildings blocks of everything.
   • In the middle of an element there is and atom.
   • They also contain protons and neutrons
   • Protons have a positive charge
   • Neutrons have no charge (they're natural)
   • The electrons move around the nucleus.
   • The electrons are negatively charged
   • The electrons are occupy by shells

2. Electron Shell

   • Electrons always occupy shells sometimes called energy levels
   • The lowest energy levels are always filled first these are the ones closet to the nucleus
   • Only a certain number of electrons are allowed in each shell: 1st shell has 2 the 2nd has 8 and the 3rd has 8
   • Atoms are much happier when they have full electron shells- like the noble gases in Group 0
   • In most atoms the outer shell is not full and this makes the atom want to react to fill it.