periodic table intro2

PERIODIC TABLE &

PERIODIC TRENDS

Organize the following classes into categories.

Chemistry 101 Marketing 214 Art 323

Music 211 Physics 404 Speech 105

Calligraphy 324 Biology 324 Phys Ed 010

Astronomy 212 Economics 103 Sculpture 102

Writing 462 Finance 321 Poetry 209

English 104 Phys. Ed 005 Business 412

Where did the Periodic Table come from?

• 1829– J.W. Dobereiner

• Triad Classification

• 1864– John Newlands

• Law of Octaves

• 1869– Dmitri Mendeleev

• Credited with modern Periodic Table

Still Not Perfect

PotassiumAtomic Mass: 39.10 amu• Highly reactive Metal

ArgonAtomic Mass: 39.95 amu• Inert gas

*Important fact you may want to right down*

The Modern Periodic Table is based on atomic number and electron configuration, not atomic mass.

Periodic Law

• When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.

Ya’ll best line up d’em elements in order of increasing proton number

to pick out the properties!

METALS

• Have only a few electrons in outer most energy level.

• Lose e- to form positive ions (X+)

• Good Conductors• Malleable (sheets)• Ductile (wire)• Often Lusterous

NONMETALS

• More than 3 e- in their outermost orbit

• Gain electrons to form negative ions (X-)

• Dull in appearance• Brittle

METALLOIDS• Have properties of metals & nonmetals• Positioned on metal / nonmetal line• B, Si, Ge, As, Sb, Te, Po, At

A Groups = Main Group Elements

AL

KA

LI

AL

KA

LIN

E E

AR

TH

NO

BL

E G

AS

ES

HA

LO

GE

NS

CH

AL

CO

GE

NS

IA IIA VIAVIIA VIIIA

IB – VIIIBTRANSITION METALS

INNER TRANSITION METALS(Lanthanide & Actinide Series)

VAIVAIIIA

3B 4B 5B 6B 7B 8B 1B 2B

Coinage Metals

Pick a Trend, Any Trend

1. Atomic Size

2. Ionization Energy

3. Electron Affinity

4. Electronegativity

Atomic Radius:

No definite shape, but scientist can get a rough measure.

Atomic SizeIt doesn’t depend on Weight Watchers

Ionization Energy

The energy required to remove an electron from an atom in the gas phase.

A(g) + Energy A+(g) + e-

Ionization energy measures how tightly an electron is held in the atom.

Ionization Energy (cont.)

• More and more energy is required to move each electron from an atom

• Metals generally have low IE.

• Nonmetals have high IE.

• IE increases as you move across a period and decreases as you go down a group or family.

Electron AffinityEA – It’s NOT a clothing company

• The energy used or released for a gaseous atom to gain an electron.

A(g) + e- A-(g) + Energy

Electron Affinity (cont.)

In general. . . • EA increases (becomes more negative) as you go across a

period and decreases as you go down a group or family.

• The greater the electron affinity, the greater the IE.– Metals have lower EAs– Nonmetals have higher EAs

Electronegativity

A comparative scale relating the abilities of elements to attract electrons when their atoms are combined.

• Active metals (IA) have the lowest Ens

• Most nonmetals have the highest Ens

And Now a guest appearance by Mr. Tom Lehrer