Chapter 5 p.123 Periodic Table

Periodic means = Repeating pattern

Dimitri Mendeleev Russian chemist,

1866, published in 1869

Mendeleev- discovered pattern by chemical properties---- left empty spaces…

42 yrs later …Henry Mosely English chemist 1911

Modern definition of Atomic# = modern organization of Periodic Table.

• PT divided into two sections

• Metals / non-metals via stair steps

• Metals on the left of stairs• Metals conduct electricity & heat

• Non-metals on the right of stairs• Non-metals do not conduct electricity very well and

heat only slightly. Most are gases and powders.

• Metalloids • Elements touching the stair steps

» Exclude Boron and Aluminum

• Properties of both, “can’t make up their mind”• “Semi-conductors” ….used in computer chips

• Elements going sideways period

• Elements going down group or family

• Period numbers down side tell largest occupied energy level. • Group numbers across the top tell number of valence electrons.

there are some deviations

transition elements, the group # equal the sum of the s & d electrons. *

Important Concept

• There are patterns to the Periodic Table called the Periodic Law

• #1 Groups or families exhibit same characteristics.

• Note: outer valence electrons determine chemical properties SO…..all elements in a group or family will have similar chemical properties.

• Official way to say it : The physical & chemical properties of elements are a periodic function of their atomic number.

• Group 1 Alkali Metals » Very reactive, explosive, does not exist pure in nature

• Group 2 Alkaline-Earth Metals» Very reactive but not as active as group 1 does not exist pure

in nature

• Group 3-12 Transition Metals » Less reactive, some not reactive, good conductors of

electricity, heat

• Group 17 Halogens » Very reactive, gases

• Group 18 Noble Gases» Not reactive, inert,

• Lanthanides» Extremely similar, tedious to distinction

• Actinides » Radioactive, short life

• Group 1: s block “Alkali Metals”all elements in group 1 have 1 valence e-

hence… all have similar properties.

Extremely reactive…..explosive

Not found in pure state in nature

Combines vigorously with non-metals

Usually stored under kerosene

Going down group lower melting point

Li depression, bipolar, …..Gastonia

Na + Cl NaCl ….salt…..electrolytes, got to have it….

bottled water?????? …. Gatorade

K + Cl KCl ….salt……muscle cramps. eat bananas

• Group 2 Alkaline-Earth Metals s2 blockharder, denser, stronger

too reactive to be found in purity in nature

Be … emeralds….green fireworks

Mg… white fireworks, very hard,

Ca… Ca3PO4 = bones ,

CaCO3 = Concrete , Marble, limestone

Chlorophyll in plants is calcium based

Sr… Red fireworks

Ba… Medicine tracking, white chalky stuff people drink, isotopes

“ With a color pencil lightly color in groups 1 & 2 to color code the s block on your periodic block”

HYDROGEN :doesn’t share same properties as group 1

is placed above group 1 because it does have the 1s1 orbital filled.

• Transitional Metals groups 3-12 color codein each case the sum of outer s electrons and d electrons

= group number

• Fe, Co, Ni, = make steel, only these can make a magnet • Al = most abundant metal on earth

• Fe = second abundant, most used #1 • Group 11

• Cu • Ag • Au = coinage metals, nonreactive ,can be pure on earth. Group 12 Zn = used in plating… ZnO

Cd = rechargeable batteries

Hg = poisonous, accumulates in bodies, thermometers

Charles Martin hall was a 21 yr old college student in 1884 in Ohio when he first became interested in aluminum. One of his professors commented that anyone who could manufacture aluminum cheaply would make a fortune, and Hall decided to give a try.

Working in a wooden shed near his house with an iron frying pan, a blacksmith’s forge as a heat and crude galvanic cells (batteries). Hall found that he could produce aluminum by passing an electric current through molten Al2O3Na3AlF6 mixture.

By a strange coincidence, Paul Heroult, a Frenchman died the same year as Hall, and had made the same discovery about the same time.

• Non-metals color code entire p block » begin to fill p sublevel» # of valence electrons = group# -10» Most are gases @ room temp» 1 non-metal is a liquid at room temp = Br » Poor conductors of electricity and heat

• Group 17 = Halogens • F… most chemically reactive

Use to etch glass and tooth decay

• Cl … disinfective …. Swimming pools

• Br … lipstick, dyes

• I … thyroid medicine, purple vapor » Sublimination: solid gas » CO2: solid gas “never gets wet, never a liquid”

********* Note: • Diatomic Molecules =

» 2 atoms of same element chemically combine in nature

N2 O2 F2

Cl2

Br2

I2

H2

When writing these you must write them as diatomic !!!!! Or it will be wrong!!!!

Noble Gases: group 18… inert ….filled energy orbital

Laser Light shows, Neon lights

Carbon

3 forms called allotropes p. 626 in book

**Allotrope= same element different structural form

l. Diamond….. Atoms in a pyramid

2. Graphite ….. Atoms in layers. pencil

3. Fullerenes….Atoms in a sphere…coalperiodic table based on carbon-12

Silicon sand, SiO2 ….. Glass, computer chips

Nitrogen each breath is 80% N2, diatomic, fertilizers, TNT,

dynamite

• Phosphorus» Fertilizers, Match heads

• Antimony & Bismuth » Added to other metals to lower melting point » Automatic fire sprinkler

• Oxygen» 20% of air , diatomic, 2 allotropes» Ozone, O3 ….. How made ?????

• Alloys:– Brass = Cu + Zn– Bronze = Cu + Sn– Sterling Silver = Cu + Ag – Pewter = Cu + Sn + Sb

• Gold:• 100% gold = 24 karat • 92% gold = 22 karat….8% copper• 58% gold = 14 karat …42% copper• 50% gold = 12 karat ….50% copper

• What property does copper add to the gold?• What makes your skin turn green with fake gold?

• Without looking at periodic table…

• For the electron configuration write …» Group#

Period# Block

• A. (Rn) 7s1

• B. (He) 2s2

• C. (Ar) 3d104s1

• D. (Kr) 5s24d105p3

• E. (Ar) 3d74s2

• Open books p. 156 #29,30,31 ---15 minutes