Chemical Periodicity CHAPTER 14 Classification of the Elements

Chemical Periodicity CHAPTER 14

Classification of the Elements Mendeleev: organized periodic table Arranged according to atomic number Groups have similar properties

Classification & Electrons Three subatomic particles Electrons determine physical and chemical properties What are three major categories on the periodic table? What is a defining property of noble gases? what information does the periodic table give?

Four categories based on electron configurations Noble gases: outermost s and p are filled Representative elements: outermost s or p only partially filled. Group number is # of electrons in outermost energy level Transition metals: metallic elements, filling d orbitals Inner transition: filling f orbitals

Atomic Radius

Ionization Energy required to lose an electron, needs to overcome attraction of nucleus First ionization energy: energy required to remove outermost electron Second ionization energy: energy required to remove outermost electron from a +1 charge ion.

Trends in first ionization energy

Size in ions Cations: smaller radius than neutral counterparts because they have lost electrons Anions: larger than neutral counterparts, gained electron(s)

Electronegativity Tendency to attract electrons when bonded Why would noble gases not be included in electronegativity?

Electronegativity Trend

Summary of Trends