Teachers’ Club Science – Student worksheets
Form/Class
Teachers’ Club Science
Chemistry
Name
Chocolate chip mining
In this task you will be using a model to represent mining of metal ores.
Metal ores are rocks which contain metals or metal compounds.
Method

Measure the mass of cookie A.

'Mine' all of the chocolate chips and throw away the rest of the cookie.

Measure the mass of the chocolate chips.

Calculate the percentage by mass of chocolate:
percentage by mass of chocolate = mass of chocolate chips/total mass of cookie

Repeat for cookie B.
Questions
1
Which cookie contained the highest percentage by mass of chocolate?
2
In the model what represented the:
Ore?.................................................
3
Metal compound?.......................................
A mining company has found a potential new site which contains copper ore. Before they start
mining they ask scientists to test a small piece of ore to work out the percentage by mass of copper
compound that it contains.
a. Describe how they would do this.
b. Explain why it is important they do this before they start mining.
Chocolate chip mining: Teacher notes
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http://smart-learning.co.uk/teachers-club/teachers-club-science/
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Teachers’ Club Science – Student worksheets
Teachers’ Club Science
Physics/Chemistry/Biology
Form/Class
Name
In this task students carry out a model of metal ore mining by
removing the chocolate chips from two brands of cookie and
calculating the percentage by mass of chocolate chips.
The class will need:
Two packets of chocolate chip cookies - two different brands
labelled cookie A and cookie B (enough for one cookie for each pair)
Tools for mining: teaspoon, table knife, tweezers
Newspaper to cover desk
Balances
Calculators
Notes
Choose brands of cookie that look different e.g. different sizes of cookie and chocolate chip, price, one
could contain pieces of other ingredients e.g. nut (but please be aware of student allergies).
In this model the ore is represented by the cookie and the chocolate chips are the metal or metal
compound.
Before the students start the task, as them to predict which brand they think contains the most chocolate.
Discuss a fair way to find this out.
You may wish to ask students to use two cookies and calculate an average to get a more accurate
result.
In real life, scientists will test ores to work out the percentage by mass of metal compound the ore
contains. The ore will only be mined if the percentage is high enough to make the mining economically
viable.
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http://smart-learning.co.uk/teachers-club/teachers-club-science/
© Smart Learning Ltd 2015