Atoms, Molecules, Ions

Atoms, Molecules, Ions

1. Atoms

   • they have 3 sub-atomic particles: Protons, Neutrons, Electrons
     • neutrons have no charge
       • relative mass: 1
     • electrons have a -1 charge
       • relative mass: 1/2000
     • protons have a +1 charge
       • relative mass: 1
   • Atomic Number: # of protons
     • all atoms of the same element have the same proton number
   • Atomic Mass: # of protons + # of neutrons

2. Ions

   • have different # of protons and electrons
     • Positive ions (K+) have more protons than electrons
       • Negative Ions (Cl-) have more electrons than protons

3. Isotopes

   • atoms with same proton number but different neutron number
   • different isotopes of same element react the same way chemically

4. Conservation of Matter

5. Law of Multiple Proportions

6. Avogadro's Hypothesis

7. Atomic Theory of Matter