THE PERIODIC TABLE!

The Periodic Table of Elements

• Used to keep track of the different elements that are natural & man made

• Mendeleev used atomic mass.• The modern Periodic Table uses

atomic number

Organization

• The elements are arranged by increasing atomic number! (They count up in order!)

• Remember atomic number is the same thing as the number of protons

• The layout of the table (where things are located) is important; the position of things tells us information about specific elements.

# of protons = atomic number

Parts to Know:• Atomic Number: tells us

number of protons in an atom

• The number of protons and the number of electrons in an atom are always the same

• We always assume that atoms are neutral

• The atomic number is specific to each element, like our DNA or fingerprints. We can change the number, but doing so changes the element we have!

Proton = (+) chargeElectron = (-) charge

+6 plus -6 = 00 means neutral charge overall

http://www.middleschoolchemistry.com/multimedia/chapter4/lesson1

Review of each “box”

Mass #

Atomic #Order of electrons

Symbol

# Protons = 17# Electrons = 17# Neutrons = 35 – 17 = 18

Three shells:1st shell has 2 electrons2nd shell has 8 electrons3rd shell has 7 electrons

17 p18 n

…more parts…

• Chemical Symbol: letters that are used to represent the names of different elements

• The first letter is always upper case and the second letter is always lower case

• Ex: Chlorine is always Cl

Mass #

Atomic #Order of electrons

Symbol

Al the symbol for Aluminum.

Its atomic # is 13.This means it has 13

protons.Its mass is 27.

Valence Electrons

• Valence electrons are the electrons located in the LAST energy shell of an atom.

• It is important because it determines how it reacts with other atoms.

11

# Shells

How many

valence electrons

Example: Valence Electrons

2 2 3 3 3 3

1 2 5 6 7 8

Families• There are columns on the periodic table

called families.• Each family is named and they tell us the

number of valence electrons an atom has.

• Just like our families, elements in the same family have a lot in common.– Group 17 are used as cleaning products

Electron Configuration

• The bottom of each elemental box has the electron configuration.

• It tells you how many energy shells it has and how many electrons go in each shell.

• Remember: the last number tells you the number of valence electrons.

Families (usually) have the same number of valence

electrons!

This is the electron configuration. There are 4 energy shells and the number of valence electrons is

2.

Rows!

• There are 7 rows on the periodic table, they tell us the number of RINGS an atom has.

Rings = shells = energy levels

Row 1

Row 2

Row 3Row 4

Row 5

Row 6

Row 7

Row is the same thing as period number!

Metals• Metals constitute most of the

Periodic Table.• They are on the LEFT of the

staircaseProperties of metals:

1. Malleable (can be hammered)

2. Ductile (can be drawn into a wire)

3. Has luster (shiny)4. Good conductors of heat

and electricity

http://www.middleschoolchemistry.com/multimedia/chapter4/lesson3

Nonmetals

• Nonmetals are located to the RIGHT of the staircase.

Properties of nonmetals:1. Dull2. Poor conductors of heat

and electricity3. A lot of nonmetals are

gasses at room temperature

4. NOT malleable and NOT ductile

5. Brittle (easily smashed into a powder)

SULFUR

Metalloids• Metalloids are in between metals and

nonmetals and are on the staircase.Boron (B), Silicon (Si), Germanium (Ge),

Arsenic (As), Antimony (Sb), and Tellurium (Te)• Properties of metalloids:

1. They are semiconductors2. They have some properties of metals 3. They have some properties of nonmetals

Ex: Te is shiny AND brittle

Antimony

Family 1 / Group 1

• These are called the Alkali Metals.• Highly reactive, shiny, color of silver,

and very soft• Since they are in Group 1, they have

1 valence electron.

Family 2 / Group 2• These are called the Alkaline Earth

Metals.• Since they are in Family 2, they have

2 valence electrons.• They are reactive metals, the color of

silver, and are denser than group 1.

Transition Metals

• Families 3-12 are transition metals because they are transitioning from metals to nonmetals.

• Their valence electrons vary

• They are usually very colorful when combined in compounds, like CuSO4.

Families/Groups 13-16

• They have metals, nonmetals, and metalloids.

• They have the same number of valence electrons.

Key:NonmetalsMetalsMetalloidsCircle the metalloidsX in the metals

Family 17 / Group 17• These are called the Halogens.• They are all nonmetals.• They are very reactive and are poor

conductors of electricity• They usually combine with group 1

to make salts

F

Family 18 / Group 18

• These are called the Noble Gasses.• They are all nonmetals• They are unreactive, colorless,

odorless gasses at room temperature.

http://www.pbs.org/wgbh/nova/physics/hunting-elements.html

• The extra 2 rows are called the Lanthanides and Actinides and are there for a reason!– If they were placed where they belong they

would push the elements in the respective rows/periods OUT of the correct columns!

– Also, their placement would put them in Transition Metals; which means their location is more or less irrelevant, while the placement of elements in Groups 13-18 is significant.

The extra 2 periods

Lanthanides

Actinides