Navigating the Periodic Table

What is the Periodic Table? An organization of Earth's elements arranged according to atomic number, the number of protons each element's nucleus contains The structure of the periodic table corresponds directly to atomic structure. This makes the table an invaluable tool for determining the property and behavior of elements and predicting how they will interact.

Introduction to the Periodic Table In the 1860’s a Russian chemistry teacher named Dmitri Mendeleev was searching for a way to categorize and make sense of the growing number of elements for his students and invented the Periodic Chart. He placed the elements in columns (groups or families) according to their similar chemical and physical properties and in rows (periods) by increasing mass. The chart is periodic because the chemical and physical properties of the elements repeat again and again. The same way that a calendar is periodic. His brilliance came because of his willingness to leave spaces where he expected elements to be in his chart, but where none had yet been discovered. Sure enough is a few years three more undiscovered elements were isolated to fit in the holes in his chart

Groups and Periods Columns aka Groups aka Families Rows aka Periods Why is it called the “Periodic” Chart?

Group (Family) Period A column or group of columns in the periodic table; elements in one group have the same number of electrons in the outermost shell A row of the periodic table; each row corresponds to the number of electron shells in an atom of the elements in that row Elements in each group share similar chemical properties The elements in the second period each have two electron shells, and the elements in the sixth period have six electron shells

Metals vs Nonmetals Nonmetals Metals

Metals vs Nonmetals Metals are elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity. Nonmetals are elements that are generally gases or brittle, dull-looking solids, and poor conductors of heat and electricity. Physical properties include Efficient conduction of heat and electricity Malleability (can be hammered into thin sheets) Ductility (can be pulled into wires) A lustrous (shiny) appearance Generally lack those properties that characterize metals and show much more variation in their properties than metals do

Some Metal Families Alkali Metals (very, very reactive) Alkaline Earth Metals (quite reactive) Transition Metals

The Mixed Groups Families containing both metals and nonmetals The aluminum family The the six metals (and more) under the staircase

Metalloids (Semimetals) Close to the “stair-step” and often show a mixture of metallic and nonmetallic properties.

Some of the Nonmetals Halogens Noble Gases aka Inert Gases (Unreactive)

Modern Period Table