Magnetism
4 marks · EasyList two materials that magnets can attract and two materials they cannot attract.
Explain, using the idea of magnetic materials, why magnets attract some objects but not others. Give an example of a practical use of this property.
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(a) Attracts: iron, steel. Cannot attract: plastic, rubber (alternatives: wood, paper, glass, etc.).
(b) Magnets attract only magnetic materials like iron or steel because these contain domains that can align in a magnetic field. Non-magnetic materials, such as plastic or wood, have no such domains, so they are not attracted. This property is used in separating magnetic materials from waste or in magnetic clasps.
Common mistakes: Saying all metals are magnetic; Listing plastic as magnetic
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Marking points
B1 (a) · 2 marks · One mark each for stating valid magnetic and non-magnetic materials.
B2 (b) · 1 mark · Explains that only materials with magnetic properties (such as iron, cobalt, nickel, steel) are attracted; others are not.
B3 (b) · 1 mark · Gives a valid example of a practical use (e.g., magnetic separation, fridge magnets, magnetic catch on doors).
Worked solution
a) Magnets can attract: iron, steel. Magnets cannot attract: plastic, rubber.
b) Only magnetic materials have structure (domains) that align in a field. That’s why magnets don't attract wood or plastic. For example, magnets are used to sort out iron cans from rubbish at recycling centres.