Properties of Selected Elements and Common Household Substances
Introduction:
The sections of the periodic table reflect the electron configurations of the
elements and the sublevels occupied by the electrons. It is the electron configuration of
the atom that determines its chemical reactivity. An element’s position in the periodic
table is directly related to the size of the element’s atoms. The size of the atoms increases
as you go down each column and decreases as you go from left to right. Elements whose
atoms have identical arrangements of electrons in their highest energy levels have similar
properties and make up a family of elements in the periodic table (vertical columns).
Elements on the Periodic Table are grouped into metals, nonmetals and metalloids based
on some key physical and chemical properties.
Elements combine chemically to form compounds. Bulk properties (physical and
chemical) are determined by microscopic structures and interactions between atoms, ions
and molecules. Common household substances span the whole range of materials from
ionic compounds to molecular compounds, and to elements.
Purpose:
Students will investigate and determine the physical and chemical properties of
selected elements and common household chemicals to further students’ understanding of
relationships between microscopic structures/interactions and bulk properties.
Materials / Equipment:
Aluminum
Carbon
Silicon
Sulfur
Magnesium
Zinc
Copper
Nail
Hammer or other hard, solid
24 cell well plate
Forceps
Conductivity tester
1.0 M HCl, 5 mL
0.1 M CuCl2, 5 mL
Epsom salt
Alum powder
Table sugar powder
Rock candy
Table salt
Copper metal
Spatula
Mortar and pestle
Kimwipes
Distilled water
Safety:
 Always wear safety glasses and apron in the chemistry lab.
 Never eat or drink in the chemistry lab.
 Hydrochloric acid solution is corrosive to eyes and skin.
 Cupric chloride solution is toxic if ingested.
 Avoid contact of all chemicals with eyes and all body tissues.
Pre-lab questions:
 Part A – Properties of Selected Elements
1. What is an element?
2. What are the general features of the Periodic Table of Elements?
3. What is a metal?
4. What is a nonmetal?
5. What is a metalloid?
6. What are required for any material to conduct electricity?
7. What is brittleness?
8. What is malleability?
 Part B – Properties of Common Household Substances
9. What is Epsom salt? What is the chemical formula for Epsom salt?
10. What is Epsom salt used for?
11. What is table sugar? What is the chemical formula for table sugar?
12. What is rock candy? How is rock candy made?
13. What is alum? What is alum generally used for?
Procedure:
Part A – Properties of Selected Elements
Using a periodic table, determine the chemical symbol for each of the seven elements
to be tested. Fill in the chemical symbol for each element on the data table.
 Physical Properties
1. Measure the physical properties of 7 elements on bulk samples. Bulk samples
are on top of the chemical bench and clearly labeled.
2. Observe and record the color of each element in the Data Table. Is the sample
silver, gray, colored, etc…? Be very specific in recording observations.
3. Observe and record the luster of each element in the Data Table. Is the
sample lustrous and shiny, slightly shiny, dull?
4. Record any other physical properties that are observed about each element in
the Data Table. Be specific in your observations. What form is the sample
in? Is the sample crystalline, flaky, rough, smooth, flat and plate-like, rocky,
in strips? Is there any odor or are any vapors given off? (Note: Avoid
breathing any vapors directly. Instead of smelling a sample directly, waft the
vapors from the sample toward your nose.)
5. Determine whether each element is malleable or brittle. To do this, position a
nail on the sample and gently tap the nail with a hard, solid object (hammer,
piece of wood, small book) A material is malleable if it flattens or bends
without shattering. A sample is brittle if it shatters or cracks into pieces when
struck. Record your results in the Data Table.
6. Use the conductivity apparatus to test the conductivity of each sample. Touch
both electrodes to the element being tested. Make sure the electrodes are not
touching each other. Pay close attention to the relative intensity of the light.
Record accordingly.
 Chemical Properties
1. Obtain a well plate. You will be testing each element in cupric chloride
solution AND hydrochloric acid solution in the well plates. The well plate is
labeled with a combination of a letter (A to D) and a number (1 to 5). So each
well can be identified with a unique code. For example, well A5 is located on
row A column 5. Record carefully in the lab notebook. There are a total of 7
elements, so you will have 14 squares labeled.
2. Take the well plate to the chemical table and place a small piece of the
appropriate element in each labeled well. (NOTE: Do not touch any of the
elements with your hands. Use forceps to obtain each sample.)
3. Obtain one pipet full of HCl. Determine the reactivity with acid of each
sample by adding 10 drops of 1 M HCl to one well of each sample—a total of
7 wells will have the acid in them. The other 7 wells will be empty at this
point.
4. Evidence for a chemical reaction may be the formation of gas bubble and/or
discoloration on the surface of the element. Some reactions may be slow to
start—be patient. Observe and record results in the Data Table. Images may
be digitally recorded.
5. Obtain one pipet full of CuCl2. Determine the reactivity with cupric chloride
solution of each sample by adding 10 drops of CuCl2 to the remaining wells.
Observe and record the results in the Data Table. Images may be digitally
recorded.
6. After allowing the samples to react (about 5 minutes) carefully decant the HCl
off the samples with the pipet and transfer to the small waste beaker at your
station. Decant the CuCl2 into another waste beaker. Empty the solid samples
into the trash, but do NOT try to rinse the well plates! This is tricky to do
without splattering water everywhere—just let your teacher do it!
Part B – Properties of Common Household Substances
 Physical Properties of Bulk Samples
1. Measure the physical properties of common household substances on powdered
samples with the exception for conductivity.
2. Observe and record the color of each substance in the Data Table. Is the sample
silver, gray, colored, etc…? Be specific in recording observations.
3. Observe and record the luster of each element in the Data Table. Is the sample
lustrous and shiny, slightly shiny, dull?
4. Record any other physical properties that are observed about each element in the
Data Table. Be specific in your observations. What form is the sample in? Is the
sample crystalline, flaky, rough, smooth, flat and plate-like, rocky, in strips? Is
there any odor or are any vapors given off? (Note: Avoid breathing any vapors
directly. Instead of smelling a sample directly, waft the vapors from the sample
toward your nose.)
5. Determine whether each substance is malleable or brittle. There are several ways
to accomplish the task: (a) Place small amount of test substance between two
sheets of clean paper. Use tip of large stainless steel spatula to apply pressure on
the samples. (b) Place small amount of test substance into a mortar. Grid the
powdery sample. Either method would be fine. A material is malleable if it
flattens or bends without shattering. A sample is brittle if it shatters or cracks into
pieces when struck. Carefully record your results in the Data Table.
6. Use the conductivity apparatus to test the conductivity of each bulk sample.
There are only four bulk samples: table salt, alum, rock candy (which is the large
crystalline form of table sugar) and metallic copper. They are on top of the
chemical table and clearly labeled. Touch both electrodes to the element being
tested. Make sure the electrodes are not touching each other. Pay close attention
to the relative intensity of the indicator light. Record accordingly.
 Solubility in Water and Conductivity of the Resulting Solution
7. On the well plate, establish proper identification of each pure substance.
8. Fill 5 wells with distilled water to 2/3 of each well.
9. Test conductivity of each well. Observe and record results in the Data Table.
10. Take small amount of each sample and put into wells 2-5. Well #1 is kept as the
control for this part of the experiment. Prior to further analysis for each
substance, the control sample has to be tested. Observe and record solubility
results in the Data Table.
11. Test conductivity for each solution. Note: cross contamination possibility has to
be minimized. Thoroughly clean the tips of the battery tester prior to the next
measurement. Pay close attention to the intensity of the indicator light.
12. In the 6th well, fill it with tap water. Test conductivity and record findings.
13. Repeat steps 7-11 one more time.
Post-lab questions:
 Part A – Properties of Selected Elements
1. Review the data gathered for the seven elements. Sort the seven elements into
groups, based on similarities and differences in their physical and chemical
properties. Using this information plus information from your book, classify each
group as metal, nonmetal, or metalloid.
2. Are there any inconsistencies within the groups you made? Do any elements
seem to have properties of both groups? Which? Explain.
3. Look at the location on the periodic table of each of the eight elements tested in
this lab. How do the properties of these elements compare to their general
position on the periodic table? Make generalizations about the position of the
metals, nonmetals, and metalloids on the periodic table.
4. Predict the physical and chemical properties of the following elements which
were not tested in this lab—selenium, calcium, and cobalt.
 Part B – Properties of Common Household Substances
5. Are there any differences of physical properties among the 4 household
chemicals?
6. Obtain melting points for all four test chemicals via internet. Is there any trend?
7. Can the four pure substances be separated into three groups? Explain if your
answer is yes.
Extension Questions/Activities:
1. How are the structures of elements and compounds on the microscopic scales
related to the bulk properties observed in the lab?
2. An aqueous sample does not conduct electricity when the conductivity tester is
used. Does it mean the aqueous sample is pure water? Explain. (Part A)
3. Given the following melting point data, are there any generalizations you can
make about the melting points of metals versus nonmetals? Are there any
exceptions? Explain.
Aluminum
Carbon
Copper
Magnesium
6600 C
36520 C
10630 C
6490 C
Silicon
Sulfur
Zinc
14100 C
1130 C
4200C
Properties of Selected Elements
Data Table 1
Element
Aluminum
Carbon
Copper
Magnesium
Silicon
Sulfur
Zinc
Chemical
Symbol
Color
Luster
Other
Physical
Properties
Result of
Tapping
Reaction
with Acid
Reactions
with CuCl2
Conductivity
Properties of Common Household Substances
Data Table 2
Element
Epsom Salt
Alum
Powder
Table
Sugar
Rock Candy
Table Salt
Copper
Metal
Chemical
Symbol
Color
Luster
Other
Physical
Properties
Result of
Tapping
Reaction
with Acid
Reactions
with CuCl2
Conductivity