The Periodic Table

Elemental Video:

http://www.youtube.com/watch?v=1PSzSTilu_s

Why is the Periodic Table important ?

• The periodic table is the most useful tool to a chemist.

• It organizes lots of information about all the known elements.

Groups: Vertical Lines

• Elements in the same group have similar chemical and physical properties!!

Why?• They have the same

number of valence electrons.

• They will form same kind of ions.

• Combine the same way

• Elements in the same row or period, have same number of energy levels.

11Na 13 Al 15P

Lewis Dot Diagram

Symbol of the element and dots representing the valence electrons

Na ● Ca ● ● Al ●

● ●

Rule of 8

• The majority of the elements form ions in order to have 8 electrons on their last energy level. ( they want to be like the noble gases and have their last level complete)

Na and Cl

Why table salt NaCl exists in nature ?

Hydrogen • Forms H+1 ion• Hydrogen belongs to a family

of its own.

• Hydrogen is a diatomic, reactive gas: H2

• Hydrogen was involved in the explosion of the Hindenberg.

• Hydrogen is promising as an alternative fuel source for automobiles

Group 1 - Alkali Metals Li to Fr

.All have 1 valence electron

.All form X1+

• Very reactive metals.

• Soft metals.

Group 2 - Alkaline Earth Metals

Be to RaAll have 2 v.eAll form X+3

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

Transition Metals

• Elements in the middle• Less reactive, harder

metals• Includes metals used in

jewelry and construction.• Metals used in alloys

Group 3 - Boron Family

• Elements in group 13• Aluminum metal was

once rare and expensive, not a “disposable metal.”

Group 4 - Carbon Family• Contains elements

important to life and computers.

• Carbon is the basis for an entire branch of chemistry.

• Silicon and Germanium are important semiconductors.

Group 5 - Nitrogen Family• Elements in group 15• Nitrogen makes up over

¾ of the atmosphere.• Nitrogen and phosphorus

are both important in living things.

• Most of the world’s nitrogen is not available to living things.

• The red stuff on the tip of matches is phosphorus.

Group 6 - Oxygen Family

• Elements in group 16• Oxygen is necessary for

respiration.• Many things that stink,

contain sulfur (rotten eggs, garlic, skunks,etc.)

Group 7 - Halogens

From F to IAll have 7 v.eAll form X-1

• Very reactive, volatile, diatomic, nonmetals

• Always found combined with other element in nature .

• Used as disinfectants and to strengthen teeth.

Group 8 - Noble Gases

The Noble Gases

He to RnHave last level complete• VERY unreactive gases• Used in lighted “neon”

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