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Science Bank: Chemistry
Programme 3: Patterns of Reactivity
Activity 1 worksheet: Alkali metal properties
• In this activity you will be using your ICT skills to investigate some properties of the
elements in Group 1 of the Periodic Table, the alkali metals.
• Open your spreadsheet program. Enter these column headings on your spreadsheet:
Name
Symbol
Density
Melting
point/oC
Ionisation
enthalpy/kJ per
mol
• In the first two fields, enter the names and symbols of the first five members of the alkali
•
metal group, lithium, sodium, potassium, rubidium and caesium.
Use a suitable source to find the data you need to complete the table. You may have
access to this data in books or you could use the Internet. One of the best sites to look on
the Internet is:
http://www.shef.ac.uk/~chem/web-elements/
1. What trends do you notice in the following physical properties of the group 1 elements:
a) density?
b) melting point?
2. Which of the alkali metals would float on water (density 1g cm-3)?
3. Now select the data in your spreadsheet in column 2 and column 5. Click on the chart
wizard to produce a chart showing how the ionisation enthalpy changes as you go down the
group. Obtain a fully labelled print-out of your chart.
4. The ionisation enthalpy gives a measure of the energy required to remove the outermost
electron from the atom.
a) What happens to this value as the group is descended?
b) Estimate the ionisation enthalpy of francium, the last member of the group.
c) How do you explain the trend in ionisation enthalpies in this group?
© 2000 Channel Four Television Corporation
page 1 of 4
Science Bank: Chemistry
Programme 3: Patterns of Reactivity
Activity 2 worksheet: Patterns of reactivity and electrochemistry
Jamale and Rhian measured the voltage of a simple cell made by placing strips of copper and
magnesium in a beaker containing dilute acid. Here is a diagram of the circuit they used.
V
Voltmeter
Copper
Second metal
Beaker
Dilute Acid
They made more voltage measurements using different metals in place of magnesium.
Their recorded their results in a table.
Metal joined to copper
Cell voltage/v
magnesium
+2.10
aluminium
+0.80
zinc
+0.85
iron
+0.65
nickel
+0.48
tin
+0.38
lead
+0.35
silver
-0.40
© 2000 Channel Four Television Corporation
page 2 of 4
Science Bank: Chemistry
Programme 3: Patterns of Reactivity
Activity 2 worksheet: Patterns of reactivity and electrochemistry
Now try these questions:
1. The metals in the first column of the table are arranged in order of chemical reactivity. What
relationship can you see between the reactivity of the metal joined to copper and the cell voltage?
2. Which of the metals in the first column appears to give an anomalous result? Try to explain why
the behaviour of this metal does not follow the general trend.
3. Suggest why the meter used to measure the voltage gave a negative reading when silver was
joined to copper.
4. Which pair of metals in the table would give the biggest possible cell voltage? What would you
expect this voltage to be?
© 2000 Channel Four Television Corporation
page 3 of 4
Science Bank: Chemistry
Programme 3: Patterns of Reactivity
Activity 3 worksheet: Patterns of reactivity and history
Draw up a timeline showing the name, date of discovery and, where possible, the discoverer
of each of the following metallic elements:
aluminium
magnesium
caesium
nickel
calcium
potassium
copper
sodium
iron
zinc
You may be able to find the data you need for this activity in a chemistry databook. If not,
the data is available at the following Internet site:
http://www.shef.ac.uk/~chem/web-elements/
Look carefully at the order in which these metals were discovered.
1. What link can you see between the reactivity of these metals and the order in which they were
discovered?
2. Why do you think that the more reactive metals have been known to us for only about two
hundred years?
3. Sir Humphrey Davy discovered a number of reactive metals in 1807 and 1808. Try to find out
what made this possible.
4. Copper and iron are both ancient metals but bronze (an alloy of copper) was known to ancient
people long before iron. Why do you think copper is older than iron?
5. Using any patterns that you have observed in your timeline, estimate how long ago each of the
following metals was discovered:
a) silver
b) rubidium (an alkali metal)
c) barium
Check your estimates with the data source that you have been using.
© 2000 Channel Four Television Corporation
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