1. Chapter 6.1: Organizing the Elements
The Periodic Table
Chapter 6.1: Organizing the Elements

2. The discovery of the scientific method caused an increase in the rate of discovery of elements

3. J.W. Dobereiner Published a classification system of triads.
Elements grouped in sets of three with similar characteristics (chemical properties).
Problem: All known elements couldn’t be grouped into triads.

4. Dmitri Mendeleev
1869: Published a new periodic table arranging the elements in increasing atomic mass.
Predicted elements
(and properties) would fill
spaces he left in his table.

5. Modern Periodic Table

6. Mendeleev made his table before knowledge of protons identifying an atom.
The modern periodic table arranges elements in increasing atomic number.
Elements with similar properties are located in the same column (group/family).

7. Periodic Law
When elements are arranged in order of increasing atomic number, there is a periodic repetition of their
physical and
chemical
properties.

8. Three Classes of Elements
Metals
Nonmetals
Metalloids
Based on their general properties

9. Location on Periodic Table
Metals (blue) = LEFT of stair step
Nonmetals (yellow) = RIGHT of stair step
Metalloids (pink) = TOUCHING stair step

10. Metals Most elements Good conductors of heat and electric current
High luster/sheen
Solid at room temperature (not mercury)
Many ductile (can be made into wires)
Most malleable (can be hammered into thin sheets without breaking)

11. Nonmetals Greater variation in properties than metals
Most gases at room temperature
NOT metals
Tend to have properties that are opposite of metals
Poor conductors of heat and electric current
Solid nonmetals tend to be brittle

12. Metalloids
Have properties that are similar to metals and nonmetals (based on conditions like temperature, presence of other elements, etc.)