Metals, Nonmetals or Metalloids?
Rebecca Pittman, Educator, Mathematics & Science Center
Developed with funding from the Mathematics & Science Center as part of the course,
Chemistry for Middle School Teachers, Summer 2004.
Curriculum
Physical Science, Chemistry
Elements in the periodic table can be divided into three
categories: metals, nonmetals, and metalloids (semimetals).
Metals make up approximately 75% of the elements on the
periodic table and have the following physical properties:
metallic shine or luster; usually solid at room temperature;
can be hammered, pounded, or pressed into different shapes
without breaking; can be drawn into thin sheets or wires
without breaking; conduct heat and electricity; and usually
show a reaction with acids.
The 17 nonmetal elements have the opposite physical
properties: seldom have a luster; often gases at room
temperature; those present as solids at room temperature
can not be hammered or drawn without breaking; poor
conductors of heat and electricity.
The 6 metalloids have properties that lie between these
extremes: often look like metals but are brittle; neither
conductors nor insulators but make excellent
semiconductors.
Key Concepts
Overview
Materials
Elements are classified as either metals or nonmetals based on
measurements of chemical and physical properties.
conductivity apparatus*1
element samples*2
2.0M hydrochloric acid*3
microscale plates*4
Safety
Follow normal classroom safety rules. Safety goggles must be worn
while working with the acid solution.
Time
50 minutes
Grouping
Groups of 2 or 3 work well for this activity.
Procedure
1. Record the sample identity and observations for the first two columns
“Metals, Nonmetals or Metalloids”
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in the data table for each sample to be tested.
2. Use the nail and rubber hammer provided to test each sample’s
malleability. Place the nail in contact with the sample and hit the head
of the nail several times with the hammer. If a sample is malleable it
can be hammered, pounded, or pressed into different shapes without
breaking. Record “yes” or “no” in the “Malleability” column.
3. Place a small sample of each element in a different well in the
microscale plate. Test each sample’s ability to conduct an electric
current by placing both wires of the conductivity meter in contact with
the sample’s surface. If the meter’s light comes on, it is an indication
that the sample is a conductor of electricity.
4. Cover each element sample with 2.0M HCl by filling the well with this
solution. Observe for at least 2 minutes. Note any changes that
occur. Compare the rate of formation of any gases by observation of
bubble formation.
5. Fill in the table below based on your observations and the
background information given under “Key Concepts”.
Sample
Identity
“Metals, Nonmetals or Metalloids”
Color
Metallic
Luster?
(Y or N)
2
Malleable
(Y or N)
Conducts
Electricity?
(Y or N)
Reacts
with
HCl?
(Y or N)
Explain
Metal
Nonmetal
or
Metalloid?
http://mathinscience.info
Assessment
1. Which bulb below (a or b) represents a positive test for a metal?
Explain your answer.
2. Which material below is most likely to be a nonmetal? Explain your
answer.
3. Which test tube represents a positive HCl test for a metal? Explain
your answer.
4. What is a disadvantage of using a test such as the reaction with
HCl?
5. How does this lab relate to the arrangement of elements on the
periodic table?
Resources
A Periodic Table of the Elements
http://periodic.lanl.gov/default.htm
A periodic table resource for elementary, middle and high school
students provided by the chemistry division at Los Alamos
National Laboratory that includes an “ask a chemist” option.
Metallic Structures
http://www.chemguide.co.uk/atoms/structures/metals.html
This page describes the structure of metals, and relates that
structure to the physical properties of the metal.
Nonmetals
http://library.thinkquest.org/3659/pertable/nonmetal.html
A general discussion of the nonmetals that includes the option to
learn more detail about each one of them.
Physical and Chemical Properties
http://www.iun.edu/~cpanhd/C101webnotes/matter-and-energy/properties.html
This site provides definitions of physical and chemical properties
with examples.
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Physical or Chemical Change
http://www.edinformatics.com/math_science/p_chem_change.htm
This site offers definitions, examples, and an assessment to test
your understanding.
Proton Don
http://www.funbrain.com/periodic/
Learn element names and symbols using this online interactive
resource.
Teacher Notes/
Advance Preparation
*1The conductivity apparatus can be assembled using the instructions
below or purchased through a scientific education vendor.
Materials needed for each conductivity meter: Two 1.5 volt, AAA
batteries; One LED (Light Emitting Diode may be purchased at a local
electronics store); One 0.5-inch inside diameter, 4.5-inch long PVC
pipe; one approximately 6-inch length of 18 gauge solid insulated
copper wire
Assembly: Connect the two batteries in series (positive to negative) by
placing the two batteries side by side facing in opposite directions and
soldering a small length of the copper wire from the positive end of one
battery to the negative end of the other. Once the solder has solidified,
bend the wire so that the two batteries form a straight line. Clip the
positive lead of the LED (the longer lead) to a 0.75-inch length of the
copper wire. Solder the free end of the wire to the exposed positive
terminal of the battery. Solder a 4-inch length of the copper wire to the
negative lead of the LED and route it past the two batteries connected
in series. Solder a 1.5-inch length of the copper wire to the exposed
negative end of the battery. Slide the battery assembly into the plastic
pipe so that the LED protrudes slightly from one end and the free ends
of the two copper wires protrude from the other end. Fill the ends of the
pipe with silicone or with a hot glue gun. Strip a 0.25-inch section on
the exposed ends of the copper wire of insulation. When the two
exposed wires are placed in contact with a conductor the LED will glow.
The intensity of the light will depend on the strength of the conductor.
*2 Samples may be placed in capped vials for student distribution.
Sample suggestions: carbon, sulfur rolls, aluminum foil, mossy zinc,
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calcium, copper, lead, magnesium, iron filings, and mossy tin.
*3Concentrated HCl is 12M. 250 mL of 2.0M HCl may be prepared by
diluting 41.6 mL of concentrated HCl to a total volume of 250 mL with
distilled water. Remember to control the exothermic reaction by adding
acid to water. Measure approximately 150mL of distilled water into a
250 mL volumetric flask ( or a graduated cylinder will work fine for this
solution). Gradually add the measured amount of concentrated acid to
the water with swirling. After all the acid has been added, fill to the 250
mL mark with distilled water. Dispense the acid in dropper bottles.
*4Small test tubes may be substituted for the microscale plates.
The data sheet for this activity can be used as part of the evaluation.
Assign answers in each of the first three categories a value of one
point. Answers for conductivity and “metal, nonmetal or metalloid” may
be assigned a value of 3 points. The column for reaction with HCl is
usually not graded because the bubbles of gas are sometimes very
difficult to observe. Advise students that a change in the appearance of
the metal can also indicate a reaction is occurring. Answers in the last
column should be based on actual experimental data which may or may
not be correct. Emphasize the importance of repeated trials and the
need to change variables before drawing final conclusions.
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