1. Discovering the Periodic TableNe Ar Kr Xe Po Rn Ra Eu Lu Pa Ac C S Fe Cu Ag Sn Au Hg Pb
Ancient Times Cr Mn Li K N O F Na B Be H Al Si Cl Ca Ti V Co Ni Se Br Sr Y Zr Nb Mo Rh Pd Cd Te I Ba Ta W Os Ir Mg Ce Tb Er Th U P Zn As Sb Pt Bi
Midd Tc Hf Re At Fr Pm Np Pu Am Cm Bk Cf Es Fm Md No Lr He Sc Ga Ge Rb Ru In Cs Tl Pr Nd Sm Gd Dy Ho Tm Yb La Rf Db Sg Bh Hs Mt
1965-
30 elements had been isolated and identified
known elements
The Noble Gases
At the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32
Timeline of Elements Discovery
Journal of Chemical Education, Sept. 1989

2. Discovering the Periodic TableNe Ar Kr Xe Po Rn Ra Eu Lu Pa Ac C S Fe Cu Ag Sn Au Hg Pb
Ancient Times Cr Mn Li K N O F Na B Be H Al Si Cl Ca Ti V Co Ni Se Br Sr Y Zr Nb Mo Rh Pd Cd Te I Ba Ta W Os Ir Mg Ce Tb Er Th U P Zn As Sb Pt Bi
Midd Tc Hf Re At Fr Pm Np Pu Am Cm Bk Cf Es Fm Md No Lr He Sc Ga Ge Rb Ru In Cs Tl Pr Nd Sm Gd Dy Ho Tm Yb La Rf Db Sg Bh Hs Mt
1965-
The Noble Gases
At the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32
Journal of Chemical Education, Sept. 1989

3. Discovering the Periodic TableNe Ar Kr Xe Po Rn Ra Eu Lu Pa Ac C S Fe Cu Ag Sn Au Hg Pb
Ancient Times Tc Hf Re At Fr Pm Np Pu Am Cm Bk Cf Es Fm Md No Lr He Sc Ga Ge Rb Ru In Cs Tl Pr Nd Sm Gd Dy Ho Tm Yb La Cr Mn Li K N O F Na B Be H Al Si Cl Ca Ti V Co Ni Se Br Sr Y Zr Nb Mo Rh Pd Cd Te I Ba Ta W Os Ir Mg Ce Tb Er Th U P Zn As Sb Pt Bi
Midd Rf Db Sg Bh Hs Mt
1965-
The Noble Gases
At the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32
Journal of Chemical Education, Sept. 1989

4. $ Symbols are Useful c . + - x .
The use of symbols is not unique to chemistry.
Symbols can be quite helpful - when you know what they mean.
Arithmetic
Money
Music $ . c
+ - x .
“A tidy laboratory means a lazy chemist.” -- Jöns Jacob Berzelius (Swedish chemist, )
Image:
A Swedish chemist who invented modern chemical symbols.
Discovered the elements:
silicon, selenium, cerium, and thorium.
Jons Jakob Berzelius
( )

5. Discovering the Elements
Metal gold silver iron mercury tin copper lead
Symbol
Celestial body Sun Moon Mars Mercury Jupiter Venus Saturn
Day
Latin (dies) Solie Lunae Martis Mercurii Jovis Veneris Saturni
French dimanche lundi mardi mercredi jeudi vendredi samedi
English Sunday Monday Tuesday Wednesday Thursday Friday Saturday
Ringnes, Journal of Chemical Education, Sept. 1989, page 731

6. Chemical Symbols Symbols used in the 16th and 17th Century
Gold
Silver
Iron
Copper
Lead
Tin
Mercury
Sun
Moon
Mars
Venus
Saturn
Jupiter
Mercury
Ancient Astronomical Symbols
Alchemical Symbols used in the 15th Century
Fire
Air
Earth
Water
Brownlee, Fuller, Hancock, Sohon, Whitsit, First Principles of Chemistry, 1931, page 74

7. Chemical Symbols Symbols used in the 18th Century
Antimony
Water
Sulfuric acid
Copper
Sulfur
Symbols used by John Dalton
Carbon
Hydrogen
Oxygen
Silver
Sulfur
Nitrogen S
Lead
Mercury
Copper C L
Gold
Potassa
Soda G
Water
Carbon dioxide
Alcohol
Brownlee, Fuller, Hancock, Sohon, Whitsit, First Principles of Chemistry, 1931, page 74