Download The Periodic Table - Academic Resources at Missouri Western

 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
 Electrons
 Negative charge
 Atomic number tells you the number of electrons
 Resides in the “shells”, orbits, or levels
 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
 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
 Electron Configuration
 Energy Levels (Shells)
 Level I – 2
 Level II – 8
 Level III – 8 (first 20 elements) (18)
 Level IV – 32
Putting it all together . . .

Sodium Na
 Atomic
 Level
 Level
 Level
# - 11
I (Shell) - 2
II - 8
III – 1
Try this one . . .
Chlorine Cl
Chlorine Cl
Atomic # 17
Level I – 2
Level II – 8
Level III – 7
 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
 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
 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.
 Metals
 Elements with 1 – 3 electrons to lose
 Positive ion
 Non-metals
 Elements with 1 -3 electrons to gain
 Negative ion
Check this out . . .
http://www.vanderkrogt.net/elements