- Mendeleev created the periodic table to organize elements based on similarities in their chemical reactions and properties. - The periodic table is arranged in 18 vertical columns called groups and horizontal rows called periods. - Elements are classified as metals, nonmetals, metalloids, or noble gases based on their physical properties such as appearance, conductivity, state of matter, and reactivity.

1. The Periodic Table - Mendeleev created the periodic table to organize elements together based upon similarities of chemical reactions . - It is made up of 18 vertical columns called groups or families and horizontal rows or series called periods . Period Alkali Metals Alkaline Earths Nonmetals Halogens Noble Gases Lanthanum Series Actinium Series 1 2 18 17 16 15 14 13 3 4 5 6 7 8 9 10 11 12 1A 2A 3A 4A 5A 6A 7A 8A 1 2 3 4 5 6 7 Transition Metals

2. Characteristics of Metals - Shiny or lustrous - Good conductors of heat and electricity - Flexible: can be bent or shaped into wire ( ductile ) or rolled into sheets ( malleable ) - All are solids at room temperature (exception: mercury , which is a liquid ) - All have a silver colour , except for gold and copper Examples: copper ( Cu (s) ), magnesium ( Mg (s) )

3. Characteristics of Nonmetals - Solids may be dull in appearance or may have a glassy luster - Poor conductors of heat and electricity - Varied examples of solids, liquids and gases - Colours vary Examples: oxygen ( O 2(g) ), sulfur ( S 8(s) ), bromine ( Br 2(l) ) Characteristics of Metalloids - Have properties of both metals and nonmetals - Semiconductors : conduct in some conditions but not others - All are solids Examples: carbon ( C (s) ), boron ( B (s) ), silicon ( Si (s) )

4. Characteristics of Noble Gases - All are gases - Least reactive of all elements - Do not conduct electricity Examples : helium ( He (g) ), neon ( Ne (g) ) - Each element has an abbreviation. Some elements use only one character such as carbon (C) or potassium (P). - Each element has an abbreviation. Some elements use only one character such as carbon (C) or potassium (K). Others use two characters , the first being capitalized and the second , being lower case , such as calcium (Ca). - Some symbols are obvious but some have historic origins.

5. Examples : Common Name Symbol Latin Name antimony Sb stibnum copper Cu cuprum gold Au aurum iron Fe ferrum lead Pb plumbum mercury Hg hydragyrum potassium K kalium silver Ag argentum sodium Na natrium tin Sn stannum