The Periodic Table Physical Science Mr. Willis

Periodic Table Arrangement Dmitri Mendeleev created the Periodic Table in 1869 Symbols are primarily Latin The columns are called groups or families. –There are 18 groups –Chemical and physical properties in groups are similar but not identical A period is a row within the periodic table.

The Original Periodic Table

Modern Periodic Table In 1919, Henry Mosely arranged elements according to increasing atomic number

2 Significant Periods The Lanthanide Series contains "rare earth" elements #57 - #71. The Actinide Series (#89-#103) contains elements with unstable nuclei, and so are radioactive.

Alkali Metal Group Column #1 (except Hydrogen) Soft & gray Low density. Very reactive Tend to lose one electron Sodium 

Alkaline Earth Metal Group Column 2 Dark metals Relatively low density. Reactive Tend to lose 2 electrons Magnesium 

Transition Metals Columns 3-12 Varied metals Tend to be high density. 1 or 2 outer electrons Brightly colored Many react with oxygen to form oxides Cobalt 

Boron family Column 13 Tend to be lower density metals Tend to lose 3 electrons Aluminum is the most abundant Boron 

Carbon family Column 14 Dominated by C which shares electrons & forms organic compounds Form computer chips from Si Mixed nonmetals, metalloids, and metals Silicon 

Nitrogen family Column 15 Nitrogen is the most plentiful atmospheric gas Mixed nonmetals, metalloids, and metals Nitrogen 

Oxygen family/Chalcogens Column 16 Primarily nonmetals Tend to gain two electrons or share in bonding Low density Oxygen is most abundant element in earth’s crust Oxygen combines with almost every other element Sulfur 

Halogens Column 17 Very reactive Nonmetal gases Tend to gain an electron in bonding (also hydrogen) Reacts with metals to form salts Chlorine 

Noble gases Column 18 Non-reactive (inert) gases because of filled outer energy level All very low density Neon 