THE PERIODIC TABLE CH 5

Do you have your elements and symbols memorized? Make sure you print out the STUDY GUIDE AND GET TO STUDYING!Make sure you print out the STUDY GUIDE AND GET TO STUDYING!STUDY GUIDESTUDY GUIDE Get your REFERENCE TABLES READYGet your REFERENCE TABLES READYREFERENCE TABLESREFERENCE TABLES

Roman Numerals I, II, III, IV, V, 1, 2,3, 4, 5, VI, VII, VIII, IX, X 6, 7, 8, 9, 10

Organizing the Elements: Mendeleev discovered a way to classify the elements 1.He arranged the elements into rows in order of increasing mass

Mendeleev Elements w/ similar properties were in the same column / group / family Columns were organized by properties

3.Masses w/in a column increase from top to bottom 4.Periodic Table is defined as an arrangement of elements in columns, based on a set of properties that repeat from row to row

Modern Periodic Table Arranged by Atomic #, Ar and K

The Modern Periodic Table –Periods are the Horizontal rows, there are 7 periods Period # tells the # of energy levels (shells) for those elements

To the L of stairs are M (except H), R of stairs are NM Lanthanide Series—57-70 Actinide Series—

–Groups/Families are the Vertical columns, there are 18 Groups Elements w/in a group have similar chemical properties

For the 8 “A” groups, the group # is the # of valence (outershell) e-

Atomic Mass A value that depends on the distribution of an element’s isotopes in nature and the masses of those isotopes An atomic mass unit (amu) is defined as one twelfth the mass of a carbon-12 atom

METALS - good conductors of heat & electricity -Solids (except mercury) -Ductile= -Malleable= -Shiny

Color the METALS Become more Metallic

Transition Metals are located in groups 3-12 (aka B groups)

NONMETALS poor conductors of heat & electricity low boiling points so most are gases solids are brittle Fluorine is the most reactive nonmetal

Become more NonMetallic Color the NONMETALS

METALLOIDS Metalloids are elements with properties that fall between those of metals & nonmetals all touch stairs *Al is a METAL

OUTLINE the METALLOIDS

Star Questions What does the period # tell you? # of energy levels What does the A group # tell you? # of valence electrons How many periods on periodic table? 7 Other names for groups? Columns, families

Valence Electrons A valence electron (known as the outer shell electrons!) is an e- in the highest occupied energy level of an atom For the “A” groups, the group # tells how many valence e- there are.

Alkali Metals Group 1A One valence/outer shell e- Extremely reactive The reactivity increases from the top to the bottom Become more Metallic

Alkaline Earth Metals Group 2A Two valence e- Reactivity is shown by the way each reacts w/ water.

The Boron Family Group 3A 3 valence e- Aluminum is the most abundant metal in the Earth’s crust

The Carbon Family Group 4A 4 valence e- Most of the compounds in your body contain carbon Silicon is the 2nd most abundant element in the Earth’s crust

The Nitrogen Family Group 5A 5 valence e- Nitrogen & Phosphorus are used in fertilizers

The Oxygen Family Group 6A Six valence e- Oxygen is the most abundant element in the Earth’s crust

The Halogens Group 7A Seven valence e- Highly reactive (Fluorine is the most reactive NM) Reactivity increases from bottom to top Become more NonMetallic

The Noble Gases Group 8A Eight valence e- (except for Helium) Colorless, odorless, & EXTREMELY UNREACTIVE “stable elements”

Star Questions Most reactive nonmetal? Flourine Most reactive metal? Francium What is special about He? Only 2 valence e- in group A8 Describe the Noble Gases? Stable, unreactive, odorless, colorless