Activity 1
961
Teacher Sheer
http://dev.nsta.org/ssc/
Scope, Sequence, and Coordination
A Framework for High School Science Education
Based on the National Science Education Standards
Science as Inquiry
A Physical Challenge
Can elements be classified by physical properties?
Overview:
Using some common mdalhc and nonmetaliic clements. students detennine their eharacteric propel1ies.
Materials:
Per lab group:
] centrigram balancc
] miniature lamp (t1ashlight)
sand papcr
hammer
screwdriver
6-\0It battery
25-mL graduated cylinder
3 wire leads
2 alligator clips
I o\ertlow can (optional)
Sample of materials (two samples of each per group. -' to 6 g per sample):
Iron
magneslllm
aluminum
carbon
tin
silicon
copper
sui fur
Zll1C
Procedure:
Supply students with element samples of merals and nonmetals. and with a "Table of Densities:'
Samples should not be identitied by name but simply labeled A-G. They can vary in mass from about 3 to
6 grams and should be in solid. non-powdered form so that students can obtain the density quite easily.
Samples should include both metals (iron. aluminum. tin. copper. zinc. magnesium) and nOilll1etals (car­
bon. silicon. and sulfur). Have students make observations of the following properties: color, luster, mal­
leability hardness and conductivity. Thcy should design a data tablc and record their observations. Have
shldents tap cach samplc with a ham111cr to dctCl111ine if the clement is malleable or brittle. Next, they
should gently rub each sample with sand paper to detel111ine its hardness, and also record if it is shiny or
dull. Havc shldcnts construct a conductivity apparatus using the materials provided and test each sample
for conductivity-rccording whdhcr thc clement is a conductor or nonconductor. Shldents can obtain the
density by obtaining thc mass and volume of the sample (the volume can bc dete1l11ined by water displace­
ment using an overt1ow can or by noting differences in water levels in the graduatcd cylinder). After com­
pleting all tests. students analyzc their observations. detel111ine which samples arc metals and which are
nonmetals-and. fi'om known densities-the name of each element previously labeled A-G.
Background:
7
i\ Ct'I'\/ltl'
'L ' i LV
f',
-iii
eccncr~ may usc any samples of c;ci11cnts that are a, ailabic Ie. thcm and suitable for tht' acti, ity.
Thc tcst for malicability consists of tapping the sample \\'ith a hammcr. ]1' it is malleable it will flattcn
without shattering. If the sample shatters into a number of pieces. it is considered to be brittle. To test
metab and nonmetals for conductiyity. connect a six \01[ b:itlery to one side of a miniature lamp. Then
conneCl another niece of v,'irt: to the other side of the batter\. Then connect another piece of \,virc to the
oIller side of the miniatlllT lamp. Test for condllcti\it:, by touching each wire load to either side of the
substance be-in,,: testt'd. Nonmetais 'xill generally not conduct ciectricity. hOWTwr if the carbon is
graphite. i; \\'ill conduct became of tlK free ckctrons \\itbin the structure.
i
Sample Results
Element
Appearance
Crushing
Conductivity
Density
(g/cm')
car:;on
zinc
silicon
iron
tin
sulfur
magnesium
elumlnum
copper
cull black-gray
Shiny siiver
Shiny gray
shiny gray
shiny silver
dull yello\\
shiny silver
Sh'my sihJer'
shiny gold
brittle
malleable
brittle
malleabie
malleable
brittle
malleabie
malleable
malleable
yes (no)
yes
yes
yes
yes
no
1.8-23
7.1
yes
yes
1.7
2.7
8.9
yes
1.6
7.9
7.3
~
L.
-i
Variations:
Students may be asked to search for metal and nonmetal objects in the home and list how they are
Llsed. Make a 1ist and state why each item is considl'red as a metal or nonmetal.
Students may be asked to collect food and other product labels. Use thl' labels to find common ele­
ments, write the name of the elements. its symbol and research to find the purpose of using the element
in the product.
Adapted ±i'om:
.·\merican Chemical Society. Chelillll7in
V('l\·.\.
Vol. 1(3). (2). 21:').
8
(~).
1991. 1992. pp. 19-20.
0
,~ctivity
0
vol'
1
Student Sheet
SCience as Inquiry
A Physical Challenge
Can eiements be classified by physicai properties?
Overview:
Ho\\ do
\\"C
kJ1CN sUlTiething is
C1
met~ll"
This actiyity pro\ides the physic3l lests
to
determine
thi~
allS\,·cr.
Procedure:
Obtain clement sample" labelt'ci ,f., through CJ. Make observations of these properties: color. luster.
malleability. conducti\'ity and Gensity, :\ijake a data table to record your observations. first recording the
color and luster of each sample. Ne:\t. tap each sample 'Nith a hammer to detelmine if the element is
malleable (flattens out) or britlk (shattl'rs), Gemly rub each sample with sandpaper. Construct a conduc­
tivity apparatus using thl' III aterials provided and test each sample for conductivity. Observe and record
whether the results indicatc th81 the material is a conductor or nonconductor. Obtain the density of each
sample. To get thc volume, drop lhe sampk intc gradua1l'd cylinder containing water and note the ',"0;­
ume difference. Use your observations ~mcl the ""Table of Densities"" supplied by your teacher to deter­
mine \\ hich samples arc metals. which are n011metals. and the identity of each metal.
'l
Questions:
1. Which lettered samples of elements \vere metals') \\·llic h were nonmetals'?
2.
What are some common characteristics of metals"
3.
\Vhat arc some coml11on characteristics of nonmetals"
4. Could any of the elemenb you tested be called mdalloids? Which ones') Why did you classify
them in this manner')
S.
Is there any generalization you can make about the densities of metals vs. nonmetals?
6.
Identify the name of each clement you tested. e.g.. A=iron. B=zinc, etc.
7. Arc the other properties you did not report on or test in this activity that might distinguish a
metal from a nonmcta]')
8. Are there any properties that you observed that might gi\e yon a cIne why nonmetals are poor
conductors of electricity"
4