Getting to know the Periodic table

Get out a textbook and turn to the inside back cover.

PeriodsThe Periodic Table of Elements is so called because of the periodic trends in each row.Period = a row in the Periodic Table

Groups

Groups = columns in the Period Table

The elements in each group share properties

Families (Overview; only write first bullet)Families in the Periodic Table share properties. Often they are the same as groups, but not always.The families we’ll get to know are:

Alkali metalsAlkaline earth metalsTransition metalsHalogensNoble gases

Other categories we’ll learn are:MetalsNon-metalsMetalloids (semi-metals)LanthanidesActinides

Metals, Nonmetals & metalloids(also overview - don’t copy this slide)

There is a stair-step line on the right side of the Periodic Table. It separates the metals from the non-metalsAlong the line on either side are elements that show some properties of metals and some properties of non-metals. These are the metalloids.

Metals(Resume notes)

Most of the elments are metals. They are found on the left side of the Periodic Table. Properties they share include:

Solid at room temperature (except mercury)Shiny (reflective)Conduct electricity (and heat) wellMaleable (they bend, not break)Ductile (you can make them into a wire)

Non-metalsNon-metals are found in the upper right of the Periodic Table. Properties they share include:

Poor conductors of electricity (and heat)Not shinyThe solids are brittle (they break, not bend)

MetalloidsAka, semi-metalsHave some metal and some non-metal propertiesMany are semi-conductors (conduct electricity under certain circumstances), making them useful in electronics.Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium, (and sometimes Astatine)

Alkali MetalsGroup 1, except HydrogenSoft metalsMost reactive elements in the PT - especially with halogens. More reactive toward bottom.Only one outer (valence) electronVideo demo: http://video.google.com/videoplay?docid=-2134266654801392897&q=chemistry+sodium#

Alkaline earth metalsGroup 2Very reactive (2nd only to the Alkali Metals)Just 2 outer (valence) electrons

Transition Metals

The center block of elementsExcept for Mercury, most are very hard, with high melting points.Basically they all have complicated ways of packing more electrons into the atoms

Lanthanides & ActinidesLanthanides: Soft, silvery and very reactive (tarnishing in air and reacting slowly with water. Called “rare earths”, many are not so rareActinides: All are radioactiveBoth these groups have complex ways of packing in more electrons

HalogensGroup 17 (7A)Non-metalsVery reactive, especially with Alkali Metals and Alkaline Earth MetalsMore reactive toward top7 outer (valence) electrons

Noble Gases

Group 18 (8A)They are inert: don’t chemically react (combine) with other elements unless forced to do soAll are gasesFull/complete outer (valence) shell of electrons

HomeworkRead Lesson10, pg 43-50.Do questions 4-8