Introduction to the Periodic Table

November 4, 2014

Our Objectives

v  Describe the arrangement of elements in the modern periodic table

v  Understand the trends that established the modern periodic table

v  Locate periods and groups in the period table

A Little Bit of the History..

v  Mendeleev first organized the periodic table by atomic mass

v But, the modern day periodic table is organized by atomic number

Dmitri Mendeleev

A Little Bit of the History..

Mendeleev’s original Periodic Table

How are Elements Classified?

Three Regions

- Metals, Nonmetals, and Metalloids

Properties of Metals

v Metals are:

v Good conductors of heat and electricity

v Shiny

v Ductile (can be stretched into thin wires)

v Malleable (can be pounded into thin sheets)

v Mostly solid at room temp (except Hg)

Properties of Non-Metals

v Non-metals are:

v Poor conductors of heat and electricity

v Not ductile or malleable

v Brittle and break easily

v Dull

v Mostly gases Sulfur

Properties of Metalloids

v Metalloids (metal-like):

v Have properties of both metals and non-metals

v Are solids that can be shiny or dull

v Conduct better than non-metals but not as well as metals

v Are ductile and malleable

Silicon

OK, Let’s Review…

v  What are some examples of metals? v Gold, silver, magnesium, lead, alumnium

v  What is a metal that is liquid at room temp? v Mercury

v  What are some examples of non-metals? v Oxygen, fluorine, nitrogen, sulfur

v  What are some of the characteristics of the metalloids ?

v Better conductors than non-metals, are shiny or dull, etc.

The Periodic Table

v  “A” groups are referred to an the representative elements because they possess a wide range of chemical and physical properties

v “B” groups are referred to as the transition metals v Notice their number is not in consecutive order from left

to right on as with the “A” groups

Periods: Horizontal Rows

Groups/Families: Vertical Columns

A 1, 2 A (3-8)

Let’s Look at the Families

•  Alkali •  Alkali Earth

•  Halogen

•  Noble Gases

Alkali Metals

v Elements in1st column (Group 1 or 1A)

v Not including hydrogen

v Very reactive metals, always combined with something else in nature (like in salt)

v Soft enough to cut with a butter knife

Li

Na

K

Rb

Cs

Fr

Alkaline Earth Metals

v Second column(Group 2 or 2A)

v Reactive metals that are always combined with nonmetals in nature

v Several of these elements are important mineral nutrients (such as Mg and Ca)

Be

Mg

Ca

Sr

Ba

Ra

Halogens

v Elements in group 17 or 7A

v Very reactive, volatile, diatomic nonmetals

v Always found combined with other elements in nature

v Used as disinfectants and to strengthen teeth.

F

Cl

Br

I

At

The Noble Gases

v Elements in group 18 or 8A

v VERY unreactive, monatomic gases

v Used in lighted “neon” signs

v Used in blimps to fix the Hindenberg problem

v Have a full valence shell

He

Ne

Ar

Kr

Xe

Rn

OTHER GROUP NAMES

•  Group 3A or 13: BORON Family •  Group 4A or 14: CARBON Family •  Group 5A or 15: NITROGEN Family •  Group 6A or 16: OXYGEN Family