Metal corrosion

Metal corrosion

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about fair testing and reading information from a graph.
10 g of each of the following metals: copper, iron, magnesium, and zinc were polished, and then left to corrode on a shelf in a laboratory for 3 months. They were then polished again, the mass loss worked out, and the results graphed.

Mass loss of metals

a)
Which metal corroded the most?   ____________________
 
b)
How much iron corroded?   ____________________ g
 
c)
How much zinc was left?   ____________________ g
 
d)
What was the total mass of all the metals after 3 months? (Show your working).
 
 
 
__________ g.
 
e)
Write an aim for this experiment.
 
 
 

f)

Why were the metals polished at the end of 3 months?
 
 
 
 
 

g)

Why was the starting mass of each metal the same?
 
 
 
 
Task administration: 
This task can be completed with pencil and paper.
Level:
5
Description of task: 
Students are given an outline of an investigation on metal corrosion and a graph of some results. Students' ability to interpret the graph and knowledge of fair testing is assessed via short answer questions.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask.
Capability: Interpret representations
This resource provides opportunities to discuss reading and interpreting a graph. 
Science capabilities: 
Answers/responses: 

  

Y10 (09/2001)

a)

Magnesium

easy

b)

4

easy

c)

2

easy

d)

Any 1 of:

Working

  • Mass loss = 0.5 + 4 + 9 + 8
Answer
  • 21.5
or
 
Working
  • 40 – 21.5
Answer
  • 18.5

Working - moderate

Correct answer - difficult

e)

Any 1 of:

  • To see if metals corrode at the same rate.
  • To see which metal corrodes fastest/the most.

easy

f)

To remove corrosion.

difficult

g)

Any 1 of:

  • To keep everything the same.
  • To compare the rate of corrosion or % corrosion more easily.
  • To make it a "fair test".

easy

Diagnostic and formative information: 
 

Common errors

a)

Copper – 25% of students' answers.

b)

6 grams – 18% of students' answers.

c)

8 grams – 28% of students' answers.