TOC 9/17/2013 Organization of Periodic Table

I. Starter• Where are some places you have

visited that have areas or items organized into categories? (Write your responses here)

As a group, create your own system of

organization for the items in the bag. Properties/Characteristics of these items & the

name of aisle/category/location should be included.

Display your system of organization on the desk and be prepared to explain how and why you organized it in a particular way.

II. Practice

I II III IV V VI VII VIII

1

2

3

4

III. Application- What patterns do you see?- What do you notice about the rows?- What do you notice about the columns?- How would we relate this to the Periodic Table?

Notes go here! Let’s tie it all together

IV. Connection

THE ATOM

To understand the information on the Periodic Table, we must first understand the simple structure of an atom.

The atom has a nucleus located in the center. Inside the nucleus are the atom’s protons

and the neutrons. Surrounding the nucleus are electron shells

or energy levels. Orbiting the electron shells or energy levels

are the atom’s electrons. An atom may have 1 – 7 electron shells. No matter how many shells the atom has, the

last one is always called it’s valence level.

Why is the Periodic Table important to

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

You get to use it on every test.

It organizes lots of information about all the known elements.

Pre-Periodic Table Chemistry … …was a mess!!!

No organization of elements.

Imagine going to a grocery store with no organization!!

Difficult to find information.

Chemistry didn’t make sense.

Dmitri Mendeleev: Father of the Table

HOW HIS WORKED… Put elements in rows

by increasing atomic weight.

Put elements in columns by the way they reacted.

SOME PROBLEMS… He left blank spaces

for what he said were undiscovered elements. (Turned out he was right!)

He broke the pattern of increasing atomic weight to keep similar reacting elements together.

The Current Periodic Table

Mendeleev wasn’t too far off. Now the elements are put in rows by

increasing ATOMIC NUMBER!!

The horizontal rows are called periods and are labeled from 1 to 7.

The vertical columns are called groups are labeled from 1 to 18.

Groups…Here’s Where the Periodic Table Gets Useful!!

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

(Mendeleev did that on purpose.)

Why??• They have the same

number of valence electrons (on outside energy level).

VALENCE ELECTRONS

Electrons in an atom’s outermost energy level that are used when atom’s bond!

6P6N

4 Valence E-

Carbon

Groups/Families on the Periodic Table

Vertical columns Numbered 1-18 Families have names

rather than numbers.

Reactivity

Reactivity is a chemical property that determines how elements will react with others to form compounds.

The MOST reactive Metals are in Group 1 & 2 The MOST reactive Non-Metals are in Groups 6

& 7 Group 18 is the least reactive of all! It’s

HAPPY…Why??

Periods

Rows Arranged according to atomic number Do not have similar properties Same number of energy levels (rings) 1st period = 1 energy level

2nd period = 2 energy levels

V. Exit

ON A NOTECARD, ANSWER THE FOLLOWING QUESTIONS IN COMPLETE SENTENCES!

• Where are the periods located on the periodic table? • What do all of the elements in the same period have in

common?• Where are the groups/families located on the periodic

table?• What do all of the elements in the same group have in

common?• What is the significance of valence electrons in an

element?