Be able to read and understand the block
The Periodic Table
Why is the Periodic Table important to me?
• The periodic table is the most useful tool to a chemist.
• You get to use it on almost every test.
• It organizes lots of information about all the known elements.
Pre-Periodic Table Chemistry …
• …was a mess!!!• No organization of
elements.• Imagine going to a
grocery store with no organization!!
• Difficult to find information.
• Chemistry didn’t make sense.
Dmitri Mendeleev: Father of the Table
• Russian Chemist• Mendeleev was the first
scientist to notice the relationship between the elements
• Published the first version of the periodic table in 1869
• Arranged elements according to increasing atomic mass
• His periodic table had gaps
Mendeleev’s Table
Why do you think there are question marks here?Image taken from: http://www.chemsoc.org/networks/learnnet/periodictable/post16/develop/mendeleev.htm
Mendeleev’s Published Periodic Table of Elements
Mendeleev’s Predictions
• Although Mendeleev’s Periodic Table of Elements had missing elements or “gaps,” he was able to predict the characteristics of these missing elements because of Periodic Law.
Date Predicted
1871 Date Discovered
1886
Atomic Mass 72 Atomic Mass 72.6
Density 5.5 g/cm3 Density 5.47 g/cm3
Bonding Power
4 Bonding Power
4
Color Dark Gray Color Grayish White
“Ekasilicon” GermaniumNotice how
Mendeleev’s predictions
(orange column) were
veryaccurate when compared to Germanium’s
actual characteristics
(green column)
Dmitri Mendeleev: Father of the Table
HOW HIS WORKED…
• Put elements in rows by increasing atomic mass.
• Put elements in columns by the way they reacted.
SOME PROBLEMS…• He left blank spaces
for what he said were undiscovered elements. (Turned out he was right!)
• He broke the pattern of increasing atomic mass to keep similar reacting elements together.
http://www.youtube.com/watch?v=fPnwBITSmgUhttp://www.youtube.com/watch?v=cvRcUeWjBu0
Henry Moseley (1887-1915)• Made improvements to
Mendeleev’s Periodic Table• Moseley later discovered that
the periodic nature of the elements was associated with atomic number, not atomic mass
• Arranged elements by atomic number instead of mass
• Realized that there were still undiscovered elements
The Current Periodic Table
• Mendeleev wasn’t too far off.
• Henry Moseley rearranged the periodic table and now the elements are put in rows
by increasing ATOMIC NUMBER!!
• The horizontal rows are called periods and are labeled from 1 to 7.
• The vertical columns are called groups are labeled from 1 to 18.
Groups…Here’s Where the Periodic Table Gets Useful!!
• Elements in the same group have similar chemical and physical properties!!
• (Mendeleev did that on purpose.)
• Why??• They have the same
number of valence electrons, number of electrons on the last energy level.
• They will react with other elements in similar ways.
Valence electrons-How many electrons are in the outermost
shell?
SiGe
Families on the Periodic Table
• Columns are also grouped into families.
• Families may be one column, or several columns put together.
• Families have names rather than numbers. (Just like your family has a common last name.)
Families of the Periodic Table
What’s in a square?• Different periodic tables
can include various bits of information, but usually:– atomic number 1– Symbol H– atomic mass 1.0007– number of valence
electrons– state of matter at room
temperature.
Representative Elements• Groups 1-2 & 13-18• 1 Alkali Metals• 2 Alkaline Earth Metals• 13 The Boron Family• 14 The Carbon Group• 15 The Nitrogen Group• 16 The Oxygen Group• 17 The Halogens• 18 The Noble Gases
Transition Elements
• Groups 3-12
• Transition Elements
• All transition elements are metals.
• Group 11 (The Coinage Metals)
• The Lanthanides
• The Actinides
• https://www.youtube.com/watch?v=OairdijvADE
• Summary
• End of first Powerpoint
Hydrogen• Hydrogen belongs to a family
of its own.
• Hydrogen is a diatomic, reactive gas.
• Hydrogen was involved in the explosion of the Hindenberg.
• Hydrogen is promising as an alternative fuel source for automobiles
Alkali Metals• 1st column on the
periodic table (Group 1) not including hydrogen.
• Very reactive metals, always combined with something else in nature (like in salt).
• Soft enough to cut with a butter knife
Alkali Metals
• http://www.open.edu/openlearn/science-maths-technology/science/chemistry/alkali-metals
Alkaline Earth Metals
• Second column on the periodic table. (Group 2)
• Reactive metals that are always combined with nonmetals in nature.
• Several of these elements are important mineral nutrients (such as Mg and Ca)
Transition Metals
• Elements in groups 3-12
• Less reactive harder metals
• Includes metals used in jewelry and construction.
• Metals used “as metal.”
Boron Family
• Elements in group 13
• Aluminum metal was once rare and expensive, not a “disposable metal.”
Carbon Family• Elements in group 14• Contains elements
important to life and computers.
• Carbon is the basis for an entire branch of chemistry.
• Silicon and Germanium are important semiconductors.
Nitrogen Family• Elements in group 15
• Nitrogen makes up over ¾ of the atmosphere.
• Nitrogen and phosphorus are both important in living things.
• Most of the world’s nitrogen is not available to living things.
• The red stuff on the tip of matches is phosphorus.
Oxygen Family or Chalcogens
• Elements in group 16
• Oxygen is necessary for respiration.
• Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.)
Halogens• Means salt former
• Elements in group 17
• Very reactive, volatile, diatomic, nonmetals
• Always found combined with other elements in nature .
• Used as disinfectants and to strengthen teeth.
The Noble Gases
The Noble Gases
• Elements in group 18• VERY unreactive,
monatomic gases• Used in lighted “neon”
signs• Used in blimps to fix the
Hindenberg problem.• Have a full valence
shell.
• http://www.open.edu/openlearn/science-maths-technology/science/chemistry/noble-gases
• http://www.youtube.com/watch?v=Uy0m7jnyv6U
• Meet the Elements
• http://www.youtube.com/watch?v=-wu0LixSBpk
http://laughingsquid.com/the-periodic-table-of-elemental-discoveries-by-country/
• Elements on the periodic table can be grouped into families bases on their chemical properties.
• Each family has a specific name to differentiate it from the other families in the periodic table.
• Elements in each family
react differently with
other elements.
Families on the Periodic Table
•Each row is called a “period”
•The elements in each period have the same number of shells
www.chem4kids.com
•Each column is called a “group”
•Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.
Except for He, it has 2 electrons
•The electrons in the outer shell are called “valence electrons”
www.chem4kids.com
Periodic table song
• http://www.youtube.com/watch?v=zUDDiWtFtEM&feature=youtube_gdata_player
• "Hunting the Elements" NOVA special http://www.youtube.com/watch?v=ct3ubD47gTE
(2012) NOVA show Hunting The Elements http://www.pbs.org/wgbh/nova/physics/hunting-elements.html
lecture series with Peter Wothers is really, really good: The Modern Alchemist: Air : Ri Channel It covers something we all experience with every breat
This PowerPoint was kindly donated to
www.worldofteaching.com
http://www.worldofteaching.com