The Periodic TableThe Periodic Table

Types of Elements

Metals► Left side of periodic

table (80%)

► Conduct heat and electricity

► Reflect light

► Solids at room temperature (one exception)

Metals

►Malleable ►Ductile

Nonmetals►Upper-right

►Great variation in properties

►Most gases, some solids, one liquid at room temperature

Nonmetals►Poor conductors of

heat/electricity

►Brittle

Metalloids►Along stair-step line

►Behave like a metal in some conditions, nonmetal in others

Development of the Periodic Table

Dimitri Mendeleev►Russian scientist►Published first

USEFUL periodic table

►Did not know atomic structure, so he arranged atoms by mass

Mendeleev’s Periodic Table►Spaces left for

“missing” elements

►Were later discovered

Periodic Law►When atoms are

arranged by atomic number (or atomic mass, in Mendeleev’s case), there is a periodic repetition of physical and chemical properties

Using the Periodic Table►Atomic Number - # of protons►Atomic Mass/Weight – Weighted average of

mass numbers of all isotopes

Periodic Table Layout

Alkali MetalsAlkali Metals►Group 1A (except for Group 1A (except for

hydrogen)hydrogen)► Comes from arabic word Comes from arabic word

meaning “the ashes” meaning “the ashes” because wood ashes are because wood ashes are rich in sodium and rich in sodium and potassiumpotassium

► EXTREMELY reactiveEXTREMELY reactive

Alkaline Earth MetalsAlkaline Earth Metals►Group 2AGroup 2A► Silver-colored, soft, Silver-colored, soft,

and low density and low density metalsmetals

► Very reactiveVery reactive

HalogensHalogens► From the Greek “salt-generating”From the Greek “salt-generating”► Group 7AGroup 7A► Elements end in “–ine”Elements end in “–ine”► Only group which contains all three states of Only group which contains all three states of

mattermatter► EXTREMELY reactiveEXTREMELY reactive

Noble GasesNoble Gases►Group 8AGroup 8A► Rarely take part in chemical reactionsRarely take part in chemical reactions► Extremely low boiling points; rarely exist as Extremely low boiling points; rarely exist as

liquidsliquids► Used in lighting and lasersUsed in lighting and lasers

Transition MetalsTransition Metals► ““B” groups of Periodic TableB” groups of Periodic Table► All solid metals, except for MercuryAll solid metals, except for Mercury► Strong, dense (often silvery-blue) solids Strong, dense (often silvery-blue) solids

that make colorful solutionsthat make colorful solutions

Co Cr Ni Cu Mn

Inner Transition MetalsInner Transition Metals► f-block of Periodic f-block of Periodic

TableTable

► Usually unstableUsually unstable

►Often radioactiveOften radioactive

►Homework:Homework:

►As the atomic number of an element As the atomic number of an element increases, the stability of that element increases, the stability of that element decreases. Explain why.decreases. Explain why.