Science Buddies: "Ask an Expert"

Hi, I have a question about the Lewis Dot diagram. What is the pattern for the period 2 elements and the period 3 elements in the Lewis Dot Diagram?

Thanks -Drea

Hi Dreaaaa14,

The Lewis Dot Diagram is a graphical way to represent the number of valence electrons or ion configurations of an element. Therefore, a Period 2 (IIA) element has two dots (representing two valence electrons) and a Period 3 (IIIA) would have 3 dots. Be careful in that period IIIB elements can have varying valence levels. To learn how to draw the Lewis dot diagram, I would recommend taking a look at this video on youtube http://www.youtube.com/watch?v=y6QZRBIO0-o

I hope this helps! Have Fun!

Marc

Hi Again,

Here is another reference for the periodic table http://web.jjay.cuny.edu/~acarpi/NSC/4-pertab.htmThe "B" series of the periodic tables reperesents Transition Metals.... so as long as your dealing with column IIIA (B, Al, Ga, In, Ti) the valence will be 3.

Best of Luck,

Marc

Hi,

Marc has given you a really good video on how to draw the Lewis diagrams. Usually the rows pf the periodic chart are referred to as the periods, and the columns are called groups.. Period one (Hydrogen and helium) only have two electrons maximum in the Lewis structure. All other periods have 8 electron positions in the Lewis disagram so rows 2 and 3 (periods 2 and 3) have 8 maximum electrons in the valence shell per the video, so the A columns fill up electrons 1 to 8, then the B columns restart from 1 to 8 electrons. Here are some websites that have example structures (note sometimes people draw a single straight line for each pair of electrons shared between paors of atoms, other times they show dots for each electron):

http://www.stolaf.edu/depts/chemistry/c ... /js/lewis/

http://en.wikipedia.org/wiki/Lewis_structure

http://hyperphysics.phy-astr.gsu.edu/hb ... lewis.html

http://www.chem.lsu.edu/lucid/tutorials ... orial.html

http://www.ausetute.com.au/lewisstr.html

http://www.wisc-online.com/objects/inde ... ID=GCH6404

http://www.roymech.co.uk/Related/Chemis ... cture.html

I hope this helps clarify the subject for you.

Best regards,

Barrett L. Tomlinson