Page 65 - 新思维科学学生用书7 样章

2 Materials and their structure

Think like a scientist

Using iron and sulfur

You are going to use iron and sulfur to make a mixture and a compound. This will help
you understand the differences between a mixture and a compound.

You will need:
• safety glasses, beaker, stirrer, boiling tube, test tube holder,
Bunsen burner, powdered sulfur, iron filings, mineral wool

Safety
Do not touch your face or eyes when handling the iron filings. The pieces have sharp

edges and can damage your skin and eyes. Wear safety glasses. Use the mineral wool
to plug the mouth of the boiling tube. Carry this activity out in a well-ventilated room.
Mixing iron and sulfur

1 Place some iron filings in a beaker.
2 Add some yellow powdered sulfur.
3 Stir the mixture so that the two
elements are spread out evenly.

You now have a mixture of
iron and sulfur. The iron and
sulfur both still have their
properties. They have not
changed chemically in any way.

The different properties of the
two elements can be used to
separate them from the mixture.

4 Use a magnet to remove the iron filings.
Making a compound from iron and sulfur
1 Make a mixture of iron and sulfur, just as you did in steps 1–3.

2 Heat some of the iron and sulfur mixture in a boiling tube.
3 Stop heating as soon as the mixture starts to glow. The iron and sulfur will
combine together and form iron sulfide.
4 Leave the tube to cool.

5 Use a magnet to try to separate the iron. You can try through the wall of the tube.

64