1. Atomic Structure • The Atom • Smallest unit of an element that can exist alone • Greek for “uncuttable” • Anatomy of an Atom: Electrons, Protons, Neutrons • The Nucleus • Proton • Positive charge • Determines the atomic number • Number of Protons determines the number of Electrons • Neutron • No charge • Atomic weight - # of Protons = # of Neutrons

2. Atomic Structure • Electrons • Negative charge • Atomic number tells you the number of electrons • Resides in the “shells”, orbits, or levels

3. The Periodic Table • Organized representation of the chemical elements • Dimitri Mendeleev • February 17, 1869 • 63 elements • 113 elements • Row (Period) • Left to right w/ increasing atomic number • Number from 1 to 7 • Columns (Family) • Number of electrons in the outer orbit • Groups • A Group (Representative elements) • B Group (Transition elements) • Group VIIIA • Noble or inert gases • Metals, Semiconductors, & Nonmetals • More on this later – stay tuned

5. The Periodic Table • The Element • Symbol • Atomic number • Total number of electrons • Total number of protons • Electrical charge • Electrons – minus • Protons – plus • Neutrons – no charge • Atomic weight (Nucleus) • Protons + Neutrons = atomic weight

6. The Periodic Table • Electron Configuration • Energy Levels (Shells) • Level I – 2 • Level II – 8 • Level III – 8 (first 20 elements) (18) • Level IV – 32

7. The Periodic Table • Putting it all together . . . • Sodium Na • Atomic # - 11 • Level I (Shell) - 2 • Level II - 8 • Level III – 1

8. The Periodic Table • Try this one . . . Chlorine Cl

9. The Periodic Table • Chlorine Cl • Atomic # 17 • Level I – 2 • Level II – 8 • Level III – 7

10. The Periodic Table • What does the Periodic Table Tell Us? • Element symbol & name • Atomic Number of the element • Number of electrons • Number of protons • Number of neutrons • Number of electrons in the outer shell • Atomic weight

11. The Periodic Table • Metals, Nonmetals, & Semiconductors • 80% of the elements are metals • Ion • An element with an unbalanced electron charge – either plus or minus • Positive ions – lose electrons • Metals • Negative ions – gain electrons • Non-metals • Remember – the number of protons determines the charge

12. The Periodic Table • Ions • When the number of protons is greater than the number electrons it is a positive (+) charged ion. • When the number of electrons is greater than the number of protons it is a negative (-) charged ion.

13. The Periodic Table • Metals • Elements with 1 – 3 electrons to lose • Positive ion • Non-metals • Elements with 1 -3 electrons to gain • Negative ion

14. The Periodic Table Check this out . . . http://www.vanderkrogt.net/elements