1. Boxes on the Periodic Table What do they tell us??

2. Boxes on the Periodic Table The boxes on the Periodic Table give the following information about an element:  symbol  atomic number  atomic mass

3. Symbols One or two letter abbreviation for an element’s name

4. Atomic Number (smaller) The number of protons or electrons in an atom of an element The periodic table is arranged in order of increasing atomic number

6. Atomic Mass (bigger) The average mass of one atom of an element Measured in atomic mass unit (amu) The protons and neutrons add to make up the atom’s mass – (the electrons are too small to count)

8. Calculating Subatomic Particles Atomic Number = __3_ Atomic Mass = _7__ (protons + neutrons) # Protons = _3__ (the atomic number) # Electrons = _3__ (the atomic number) # Neutrons = __4_ (7 – 3) 3 Li Lithium 6.941 Atomic Number Element Symbol Element Name Atomic Mass

9. Calculating Subatomic Particles ElementSymbol Atomic Number Atomic Mass # proton (atomic number) # electron (atomic number) # neutron (atomic mass – atomic number) Copper6429 Ca40 19

10. I have noticed… Atoms are neutral – same number of protons (+) and electrons (-)  Neutrons are neutral, so they don’t count! Only 2 of the 3 subatomic particles make up an atom’s mass; the protons and neutrons

12. And lastly… If you change the number of protons in an atom you have another element If you change the number of neutrons in an atom you have an isotope If you change the number of electrons in an atom you have an ion that is ready for bonding