Chapter 5 (cont.)

The Periodic

Table

History of the Periodic Table

• Mendeleev (1860’s)– Developed the first periodic table– It was arranged by atomic mass– He was able to predict properties of elements

History of the Periodic Table (cont.)• Moseley – developed the modern periodic

table

• His periodic table was

arranged based on atomic

number

The Periodic Table

Characteristics of Metals

• Hard

• Shiny

• Conduct heat and electricity well

• Includes the transition and inner-transition metals– Inner transition metals include the lanthanide

and actinide series

Characteristics of Nonmetals

• Are gases or brittle solids at room temp.

• Surfaces are dull

• Insulators

Characteristics of Metalloids

• Have properties of both metals and nonmetals

Period vs. Group• Period

– All elements in a horizontal row– 7 periods on the periodic table– Arranged in increasing atomic number

• Group– All elements in a vertical column– Sometimes called “families”– Have similar properties

Group 1 (IA) – Alkali Metals

Group 2 (IIA) – Alkaline Earth Metals

Group 17 (VIIA) - Halogens

Group 18 (VIIIA) – Noble Gases

Left of stair step

On the stair step

Right of stair step

METALS

NONMETALS

Metals- Nonmetals

-Metalloids-

B. Organization of the Periodic Table

METALLOIDS

TRANSITION “Group B”

INNER TRANSITION

REPRESENTATIVE

“Group A”

Group A- RepresentativeGroup B - Transition

B. Organization of the Periodic Table

The Extended Periodic Table