Iron filings, sand and salt

Iron filings, sand and salt

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about planning and carrying out an investigation.

Equipment list

  • mixture of equal parts of iron filings, sand, and salt
  • water
  • funnel
  • filter paper
  • 2 glass jars or ice cream containers
  • a magnet

a)

Using some or all of the equipment above, separate the iron filings from the rest of the sand and salt mixture. Write down in the space below how you did this. 
 
How I did this:

______________________________________________________________________ 

______________________________________________________________________ 

______________________________________________________________________ 

______________________________________________________________________ 

______________________________________________________________________ 

______________________________________________________________________ 

 
b)
Now use some or all of the equipment to separate the sand from the salt. Write down in the space below how you did this. How I did this:

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

 
 
c)
In science, properties of a material describe how it looks and how it behaves.
Explain which properties of the iron filings, sand, and salt you used to separate them from each other. Fill in the table below with your answers.
 

Student Self-Assessment Sheet
Give yourself a rating (see below) for each of the questions. Write some reasons why you gave yourself this rating.

The ratings are:

1 = Yes (I successfully did this.)
2 = I tried to do this and did a pretty good job, but I think I could do better.
3 = No (I did not do this successfully, I need to do more work.)

Now give your Student Self-Assessment Sheet to your teacher to talk about how you rated yourself.

Do they agree with your rating?

Task administration: 
Equipment:
Mixture of equal parts of iron filings, sand, and salt (in trials we used 50 g of each); magnet; water; funnel; filter paper; 2 glass jars or ice-cream containers.]
  • This task requires students to determine how they will separate iron filings and sand from a mixture of iron filings, sand, and salt. Students then explain the physical properties that allowed them to separate these three items.
  • Students need to be familiar with methods of separation including how to use filter paper.
  • Make sure students understand the word "properties" as it applies in science.
  • A Student Self-Assessment Sheet has been included with this task for the student and the teacher to complete. The teacher may need to give guidance on how to fill it in. It is suggested that the teacher and student discuss the student's rating rather than the teacher just filling in their portion.
Level:
3
Curriculum info: 
Science, Investigating in science, Material World
Keywords: 
investigation, physical properties, mixtures, separation of mixtures, developing systems, self assessment
Description of task: 
This practical task requires students to use methods of separation to separate a mixture of salt, sand, and iron filings. Students explain how they did this and the property of the substance that they used.
Curriculum Links: 
Science capabilities
The capabilities focus is brought about by the conversations you have and the questions you ask. 
 
Capability: Gather and interpret data
This resource provides opportunities to discuss processes in science and why they are useful. 
Science capabilities: 
Gather and interpret data
Answers/responses: 

a)

Students describe a method that would successfully separate the iron filings from the sand and salt mixture, e.g., using the magnet.

b)

Students describe a method that would successfully separate the sand from the salt mixture, e.g., uses the funnel lined with filter paper, adds water, and puts the sand and salt mixture inside of it, the salt dissolves into the water and just leaves the sand in the funnel.

c)

Iron filings: Attaches to a magnet.
Sand: Does not dissolve/can be filtered.
Salt: Dissolves in water.

Extension: How could you separate the salt from the water?