The Periodic Table of Elements

10th Grade Chemistry

2014-2015

Mrs. Page

Who will memorize this song??? We shall see! https://www.youtube.com/watch?v=zUDDiWtFtEM

http://www.sciencegeek.net/tables/DeltaBioLarge.jpg

Dmitri Mendeleev

•1869•Russian Chemist•Mendeleev organized the known elements based on atomic mass•He predicted that the “gaps” on the periodic table were elements that had yet to be discovered

Periods

•Periods go across the table from left to right (rows)•Periods are labelled from 1-7 •Look at your Bohr model wkst – what is the pattern (trend) for each period?•The period tells you how many electron orbitals an atom has!

http://www.chem4kids.com/files/elem_pertable.html

Families or Groups•Groups are the columns•Each group or family has similar characteristics•Look at your Bohr model wkst what is the pattern for groups?•The Group tells us the number of valence electrons

http://www.chem4kids.com/files/elem_pertable.html

General Layout of the Periodic Table

http://intro.chem.okstate.edu/1215sp2000/lecture/chapter4/lec21100.html

Metals

Nonmetals

Metalloids

Properties of Metals•Solid at room temperature (except Mercury )•Have Luster (shiny in appearance)•Good conductors or heat and electricity•Malleable (can be hammered into sheets)•Ductile (can be pulled into wire)•High Melting & Boiling Points•High Density

Properties of Nonmetals•May be solids, liquids, or gases at room temperature•Do not conduct heat or electricity well (Poor Conductors)•If solid, generally brittle•Looks dull•Low melting & boiling points•Low density

Metalloids•Share properties of both metals and non-metals•Semi-conductors – insulate and conduct (used in computer chips)

Families/Groups

http://mcguirescience.weebly.com/periodic-table.html

Alkali Metals•Group 1•Have 1 valence electron•Oxidation number: +1•Extremely reactive metals•Do not occur freely in nature•Very soft (can cut with knife)•Low melting/boiling points compared to other metals (transition metals)•Low densities (compared to other metals)•React with water explosively!

https://www.youtube.com/watch?v=uixxJtJPVXk

Alkaline Earth Metals

•Group 2•Have 2 valence electrons•Oxidation number: +2•Very reactive (but not as much as alkali metals)•Not found free in nature•Present in Earth’s crust •High melting/boiling points•Lower densities than transition metals

https://www.youtube.com/watch?v=T7K4Qi5PiFg

Transition Metals•Groups 3 – 12•Contain subshells so electron configuration gets “messy”•Valence electrons are in multiple shells•Form multiple oxidation number depending on element (always cations)•Have all the properties of metals•High melting/boiling points•High densities•Iron, cobalt, and nickel, are the only elements known to produce a magnetic field.

Rare Earth Elements

•Pulled out of group 3 and placed at bottom of periodic table•2 periods: lanthanide series and actinide series•Many are man-made elements•Very difficult to isolate – found combined with each other

Boron Family

•Group 13•3 valence electrons•If they form ions their oxidation number is +3•All metals except Boron (metalloid)

Carbon Family

•Group 14•4 valence electrons•Made up of 2 metals, 2 metalloids and 1 nonmetal•Due to half full valence shell these atoms tend to form covalent bonds (share electrons)

Nitrogen Family

•Group 15•5 valence electrons•Oxidation number: -3•Made up of 1 metals, 2 metalloids and 2 nonmetal

Oxygen Family

•Group 16•6 valence electrons•Oxidation number: -2•Made up of 1 metals, 1 metalloids and 3 nonmetal

Halogen Family•Group 17•7 valence electrons•Oxidation Number: -1•Extremely reactive•“Halogen” means “salt-former” these elements form salts when bonded to other elements (mostly alkali or alkaline earth metals)•All are non-metals•Exist in all three states of matter

https://www.youtube.com/watch?v=yP0U5rGWqdg

Noble Gases •Group 18•8 valence electrons (except He)•Full valence shells•NOT reactive•Rarely form compounds•All gases at room temperature

https://www.youtube.com/watch?v=5KiTu4dWXik

YOU SHOULD NOW BE ABLE TO: • Distinguish between periods and groups• Explain how group number and valence electrons are related (tell

the number of valence electrons in each group)• Explain how period number and electron shells are related• Describe how metallic properties change across a period and down

a group (hint: where are the metals on the periodic table? Look at Carbon or Nitrogen families to determine trend down a group.)• Describe the properties of metals, nonmetals, and metalloids• Determine how reactivity changes down a group and across a

period• Determine the oxidation number of an element• Describe the general characteristics of each family