1. Periodic Table of Elements and Atom Notes 6.4 a,b,c Atoms are made up of protons, neutrons and electrons. The nucleus contains the protons and neutrons. Protons have a positive (+) charge and neutrons have a neutral charge (no charge). The Electron Cloud contains the electrons. Electrons have a negative (-) charge.

2. In 1913, a Danish Scientist named Neils Bohr created a model of an atom, known as the Bohr model. ELECTRON SHELL MAXIUM NUMBER OF ELECTRONS THE SHELL CAN HOLD 1 2 2 8 3 8 4 18 5 6 32 7

3. Atoms of one kind of element are the same while atoms of different elements are not the same. Each element has a different atomic number which represents the number of protons that element has. So all elements have different number of protons.

4. A Russian, Dmitri Mendeleev, designed a way to organize the atoms of different elements into a chart called the Periodic Table of Elements. Atomic Number= # of Protons # Protons is equal to the # of electrons Symbol for the element Name of element Atomic Mass which = # protons + # neutrons *How do you find out the # of Neutrons? Atomic Mass - # of Protons = # Neutrons

5. Element Symbols follow one very important rule: They can only have ONE capital letter. Look at the Periodic Table of Elements I gave you and write the symbols for the following elements: Carbon Nitrogen Hydrogen Silicon Oxygen Neon Calcium Iron Gold