Transcript Periodic Table - Lompoc Unified School District

Periodic Table and Configuration
Demetri Mendeleev
 Created modern periodic
table (late 1800’s)
 Arranged by increasing
atomic mass
 Similar elements found in
columns
Modern Table
 Elements are in columns called groups or families
 All elements within a group have similar chemical properties
and can often be used to replace one another in compounds
to produce new compounds with slightly different properties
 Horizontal rows are called periods
Three Distinct Regions
 Representative elements are chemically active elements
 Transitional metals are in center of the table
 Inner transitional metals are the two rows below
1) top row called lanthanides
2) bottom row called actinides
Group Names
 Group 1 – Alkali Metals
 Group 2 – Alkaline Earth Metals
 Group 16 – Chalcogens
 Group 17 – Halogens
 Group 18 – Noble or Inert Gases
Metallic Character
 Elements can also be divided by metallic character
 Metalloid – between metal and non-metal
Configuration
 Arrangement of electrons in the atom
 Aufbau Principle – orbitals fill in order of increasing energy
Orbital Diagram of Li ( 3 e-)
 1s22s1
Orbital Diagram of B (5 e-)
 1s22s22p1
Hund’s Rule
 Electrons occupy degenerate orbitals singly first
Orbital Diagram of C (6 e-)
 1s22s22p2
Orbital Diagram of Ne (10 e-)
 Configuration 1s22s22p6
Example
 Determine the configuration of
Fe
Br
Magnetism
 When electrons in half-filled degenerate orbitals spin in the
same direction, the material is magnetic
Valence Electrons
 Outer shell electrons
 Ones in the last main energy level
▪ K 1s22s22p63s23p64s1
• Fe 1s22s22p63s23p64s23d6
1 valence e
2 valence e