Investigation
IV - Molecules in Action
Lesson 4 - Polar Bears and Penguins
ChemCatalyst
• Draw the Lewis dot structure for HeI.
• If the penguin represents a hydrogen atom and
the polar bear represents a chlorine atom, what
does the ice cream represent in the drawing?
What do you think the picture is trying to
illustrate?
• Do you think Hel will be attracted to a charged
wand? Explain your thinking.
Smells © UC Regents, LHS Living by Chemistry, 2003.
257
Investigation
IV - Molecules in Action
Lesson 4 - Polar Bears and Penguins
Polar Bears and Penguins
Name:
Period;
_
Date:
_
Purpose: In this lesson you will be exploring polarity and bonding between atoms in
greater detail. A comic book will provide new information about these topics and will
introduce you to the concept of electronegativity, which helps us to understand partial
charges.
Use the comic book called "The Bare Essentials of Polarity" to answer the following
questions.
1. How does the cornic book define a "polar molecule?"
2. Define electronegativity
the comic book.
as you understand it, after reading the first two pages of
3. Interpret the picture at the bottom of page 1. Explain how the iceberg, penguins,
and polar bears represent trends in electronegativity.
4. What is the artist trying to represent when there are two polar bears arm wrestling
together, or two penguins arm wrestling together?
5. What three types of bonds are represented on page 3 of the comic book? What
happens to the bonding electrons in each type of bond?
Smells © UC Regents, LHS Living by Chemistry, 2003.
262
Investigation
IV - Molecules in Action
Lesson 4 - Polar Bears and Penguins
6. Explain why there are four scoops of ice cream in the illustration of 02 on page 3.
7. What do the six scoops of ice cream represent in the illustration of N2 on page 4?
8. Describe what you think is happening to the penguin in the CO2 molecule in the
picture on page 4.
9. Name three things that the picture of C02 on page 4 illustrates about the
molecule.
10. Describe what you think is happening to the penguins in the illustration of H20
on page 4.
I-
11. Explain what you think the crossed arrow represents in the comic book. (
12. What are the two definitions of "dipole" given in the comic book?
Making Sense
What does electronegativity
have to do with polarity?
If you finish early ...
Using polar bears and penguins, create an illustration showing a hydrogen sulfide
molecule, H2S. (Hint: You may wish to start with a Lewis dot structure.)
Smells © UC Regents, LHS Living by Chemistry, 2003.
263
Lesson Guide: Investigation
IV - Lesson 4
Polar Bears and Penguins
-.
The cfcettic.o.l i~l~
,ELJEC'fAONEGATI.VlTY
on
CiI'tom/l'\jjjelw$
of POLA'RITY is (:Qused by diff~ren.cC$ ,in
~fWeM atoms. IEltdl"OncgatiY:ity i~ the: obllify
to atiiruct bGr'lding el0C1t~nst(il~
itse.ff.
,of
The periodic Tdble. .'lMwS CI g~l'\eij"(]il trem:! in 1ihe. e'lectron.~th;ity of the
,elements. ElectrDn.eg4fi.•••
ity' fe-I\ds 'toO rise, as Y(lU move "Mi"th~t"
01'1 the
periodi(l tobie, o;nd fell <IS you move· $outhwtsf ..•.
- -:"";;;"'-=_
--'
~ :;::">.J
~'
!J..bu!,: Tht
t»b.'Ie
.rll'.:t~*tiwty
88
g¢SSe5. mth.~
'iIOrD!
p!lt'icdfc 'I,g,b~'s10l" I'I':9Rt OOh.lIW'l.'!JM (I~tCfjJ~f9nc:d<m
of z.•••
ro bCOGU!lt
tht}l' or~ ~Iotiv~ty tlO~CQctivt.
Smells © DC Regents, LHS Living by Chemistry, 2003.
Polar Bears and Penguins
Lesson Guide: Investigation IV - Lesson 4
When two «tOMS wi'tl'i uneql.tCl eledrorlt.go:tiVi'ty value.s bond, th~ydo Mt
shar.e the bor:tding f:1f:t,tll"OlI$ evmly. Tht. bondil'l,g eleetr'On$ sJ1eind mtir',e time
Qr.ouJid tne mort eh~c:trCl1egativeQtl?m. creotirng 'Q PARTIAL NEGATIVe
CHARG:e on thal d'tOM. lheother atom then hCilS'Il PARTIAL POSITIVE
OHARGE. and the bond IS polar.
/
Smells © UC Regents, LHS Living by Chemistry, 2003.
89
Polar Bears and Penguins
Lesson Guide: Investigation IV - Lesson 4
!
fmccI.lJ~6the elemenfs ho",e such varying Il!lecrrcncgcrtivitid c,iI1dcan come
togethg in;so !Mny diffCi"tl'lt ~ombi'Mtions,tf'!ere i$ fcally o. CONTINAIM
OF IPOLARl'TY IN OONDliNe. Fo1' C(Jnl(~r\ierJC',e. we ean bl"ectk the
,conttnIUUIT\.down into t~~e OQ,1<t90I'\ies~(1) iMt.I\pohmr .r.:o!;'dl.e.f'I!t , (~) po~Qr
ccwlent, o:nd (3)itlt'l;<t.
'
ii.----~_----I-
tno po:;ol¢r~lcnt bond, two'ot~rm l.itill IlhilTt bMidM pilirs of tlutl"OM. ilvt 1MM
,~le.etroM~ d«icledlv_ Gt"II'IIlB~ 'e ~ 4toiill f.~ theotb~.el<'llmplu mclidc ticn:Ji
Ibetwl!M ~
~ 1I~4!in <lfll1ltn$. oli' k1w"-" Mydr09Jm and fJlm'ine a1~1nS:.
-
90
-
-
Smells © UC Regents, LHS Living by Chemistry, 2003.
Polar Bears and Penguins
nil\.il
Lesson Guide: Investigation IV ~ Lesson 4
U<f!.I"'~~nU,!om:.; consntu
I.1UrlU~
e 1JJ.t'CJLt::>.
ACTYQ.lIy,
the wora (f1~QI,e-coh refer 'fq
several diffelf"wt things that ctt~ f"ele-vorrf here; (1) the polarity of ern i"divir;iuQI PQIli.r
bond between atoms. (2:) the ntt pol<tfity of Q potor> m,(Ite.~u!e thaT i/'OOYha.'le :re'/eral pokl.r
tovolen1 bor!ds within it. or.d (3) 1he polar rrolu Ie i self .
.,~?~1'1l
.-/
~nN;: IM/«ule
; ," "
~
CQnfU5in9~
>$'t(t (I di,:l'lk
(it's
Let's
IOQk at s¢me
,. H:a
MtO ]!D!.:r
:101"" ~), ~ it dOi!sf,j'f h.:v~m'I'f dipol(!:l: (p;>lor
;.yM) "",,'!'hon11.
,exQIl'ples:
~ Q ~llX'ic
'F>OIQf"
~''''llc)..
(0 ~;b{~
~
ir-is c
,0,;:<1,. (1:1'
--
in the other h¢1!d.CO~ Ms ,.•••
0 t!ipold (two !!'Obi'
~)_
but the; CO. molt::tull' .H ,If b; nM Q d<pO!1.
X!:OWU itt po::4I" 'bc0ldii: (lItI'I(:c,l ~,
,,:'tiN' 4<.i' CIId
'I'IC'kt. fu~ 1'IW1C1;U'~ ~
Uilll.
1- --
~
gOND,.: ~
tMJU!IC':J{.E:
~
NCNfbtAFI..
"
v.:.A'
I
Smells © UC Regents, LHS Living by Chemistry, 2003.
91