Periodic Table Museum

HISTORY

John Newlands (1864)• proposed an organization scheme for elements

based on increasing atomic mass• noticed that the properties of elements repeated

every eighth element (1st and 8th, 2nd and 9th)– Example: he noticed the similar properties between Li

and Na, Be and Mg, N and P– Law of Octaves – repeating (periodic) relationship

every 8th element, like music notes

• criticized as “unscientific” and work not generally accepted

Dmitri Mendeleev (1869) • designed the first periodic table

based on:– Elements with similar properties

grouped together

– Increasing atomic mass

– Left blank spots, predicting properties of elements that had not yet been discovered.

Henry Moseley• Rearranged the periodic chart to its current

form based on increasing atomic number elements with similar properties grouped together.– This solved problem of misplaced elements

• Periodic Law - when elements are arranged by increasing atomic number, there is a periodic repetition of chemical and physical properties

Reading the Periodic Table

Periodic Table

Groups (or Families)– columns on the table

Elements in the same group or family have similar characteristics or properties.

Kr

Xe

Rn

Ar

Ne

He

8A

CaK Sc Ti V Cr Mn

Fe Co Ni

Cu Zn Ga Ge As Se Br Kr

Periods – rows on the tableElements in a period are not alike in properties.

States of Matter

States of Matter

Definite Shape

(does not depend on container)

Definite Volume (does not depend on container)

Effect of Temperature increase

Compressible (can squeeze into smaller

volume)

Solid Yes Yes Small expansion

No

Liquid No Yes Small/moderate expansion

No

Gas/Vapor

No No Large expansion

Yes

States of Matter

H

Li Be

Na Mg

CaK

Rb

Cs

Fr Ra

Ba

Sr

Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

XeITeSbSnInCdAgPdRhRuTcMoNbZrY

La

Ac Rf

Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Db Sg Bh Hs Mt

LuYbTmErHoDyTbGdEuSmPmNdPrCe

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Ar

Ne

He

F

ClSPSiAl

B C N O

1A

2A

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

3A 4A 5A 6A 7A

8A

Metals, Non-Metals, & Metalloids

Metals• Left side of the periodic table

–except H

• Properties:–lustrous (shiny)

–good conductors of heat & electricity

–malleable & ductile

–solids at RT (except Hg)

Non-Metals• Right side of table

–plus H

• Properties:–Dull appearance

–Brittle when solids

–Do not conduct heat or electricity well

–May be solid, liquid or gas at RT

Metalloids• Stair step between metals and non-

metals

• Properties in between metals and non-metals–Si: brittle but semi-conductor

• Many metalloids are used in computer chips to conduct electricity without conducting too much heat

Families

•very reactive metals that do not occur freely in nature

•Slivery-white and softer than most other metals (to the point that they can be cut easily with a knife)

•can explode if they are exposed to water

ALKALI METALSALKALI METALS

•They are harder, denser, and stronger than the alkali metals with higher melting points

•They are so reactive they are not found as free elements in nature

ALKLINE EARTH ALKLINE EARTH METALSMETALS

•Metals with typical metallic properties and uses

•Less reactive than group 1 and 2 metals – some are so unreactive that they exist in nature as free-elements

•Iron, cobalt, and nickel, are the only elements known to produce a magnetic field.

TRANSITION TRANSITION METALSMETALS

Inner Transition Inner Transition MetalsMetals

•Wedged between groups 3 and 4 in the sixth and seventh periods

•The lanthanides (top) are shiny and similar in reactivity to the alkaline-earth metals.

•The actinides (bottom)are all radioactive and most are man-made

ActinidesLanthanides

HALOGENSHALOGENS

•"halogen" means "salt-former" and compounds containing halogens are called "salts"

•Most reactive non-metals

•exist in all three states of matter at room temperature:•Solid- Iodine, Astatine •Liquid- Bromine •Gas- Fluorine, Chlorine

NOBLE GASESNOBLE GASES

•Nonreactive due to their complete valence shells•Do not easily gain or lose valence electrons•All gases at room temperature