Previous concepts

Previous concepts

1. MOLECULES

   • Molecules are made up of different ATOMS.
     • The nucleus of the atom is made up of
       • NEUTRONS
         • without charge
       • PROTONS
         • Positive charge
       • ELECTRONS
         • negative charge
           • The number that designates the main ENERGY LEVEL occupied by the electron around the nucleus is called the main QUANTUM NUMBER.
             • The PAULI EXCLUSION principle states that there cannot be two electrons with all quantum numbers the same.
         • VALENCE is the number of electrons that a chemical element is missing or must give up to complete its last energy level.

2. FOTON

   • The higher the frequency of the PHOTON, the greater its energy. And the longer the WAVELENGTH of photons, the lower their energy.

3. LEWIS

   • A Lewis diagram shows how valence electrons are distributed around the atoms of a molecule.