Periodic Table

first arranged the periodic table Demtri Mendeleev first arranged the periodic table arranged them by atomic mass he noticed that they had similar chemical and physical properties but some elements were out of order

Henry Mosley Arranged the elements by atomic number modern table is arranged this way periodic law: the properties of the elements are periodic functions of their atomic number Patterns

B Si As Ge Sb Te non metals Transition metals Inner transition Noble Gases Transition As Alkaline Earth Metals Halogens Ge Alkali Metals Sb Te metals Inner transition Periods Groups or Families •vertical columns • members have the same number of valance electrons •members of the group have similar chemical properties •horizontal rows •members have the same # of principal energy levels

B, Si, As, Ge, Sb, Te ONLY!!! • Luster • ductile • malleable Metals Metalloids Nonmetals • Luster • ductile • malleable • good conductors of heat and electricity • high melting and boiling pt. • semi-metals • touch a side of the staircase Has properties of both metals and nonmetals • dull • brittle solids • poor conductors of heat and electricity • low melting and boiling pt. B, Si, As, Ge, Sb, Te ONLY!!!

Group 1 - Alkali Metals valance electron(s) 1 +1 ion • most active metals • not found in nature by themselves • form stable compounds • can be obtained by electrolysis of fused salt.

Group 2 - Alkaline Earth Metals valance electrons 2 +2 ion • second most active metal • some are not found in nature by themselves

Group 17 - Halogens •valance electrons 7 •most common ion -1 • have all states of matter at room temp. F2, Cl2 gases Br2, liquid I2, solids • are the most reactive non metals

Group 18 - Noble Gases valance electrons 8 •Inert gases (non reactive) •have the most stable electron configuration- 8 e in the valence shell •Kr and Xe can react with fluorine-they have an oxidation number other than 0

Transition Elements • many oxidation numbers • valance electrons are in various energy levels --can lose electrons from more than one energy level • form colored ions in solutions

same element in various forms Diatomic Elements Allotropes Liquids Radioactive same element in various forms Different physical and chemical properties O2 O3 C- graphite diamond I Bring Clay From Our New Home All elements over #82 have no stable isotopes Br nonmetal Hg metal I2, Br2, Cl2, F2, O2, N2, H2 all other elements are monatomic

TABLE S NOTE: Leave Room in each box. We will revisit in detail Ionization Energy Electronegativity • amount of energy needed to remove an electron • the ability of an atom to attract an electron TABLE S Periodic Trends patterns on the periodic table Atomic Radius Reactivity • distance from the nucleus to the outer most energy level the ability of a substance to undergo a change

Ionization Energy •lower the energy -easier to remove • across periods value increases • move down a family (group) decrease harder to remove e-’s from non-metals -they need more to be stable; easier to remove from metals- they want to get rid of them.

Electronegativity • 0-4.0 range (4.0 is highestest) • move across a period increases • move down a family decreases non metals want e-’s so they will be attracted to them; metals want to get rid of e-’s so they will not be attracted to them

Atomic Radius • period: decrease as you move across because increase in nuclear charge(+) •group: increase as we go down because increasing number of energy levels in an atom

Reactivity • metals: left and down • most active metal Fr • nonmetals; right and up • most active non metal F

IE increases EN increases Radius decrease IE decreases EN decreases Radius increase nonmetal metal Reactivity

Atomic vs. Ionic Size Nonmetals Metals gain electrons lose electrons become negative ions Ion is larger than atom lose electrons become positive ion ion is smaller than atom Cl + 1e Cl- Na Na+ + 1e