Magnets and their Properties – Part 2 Date Magnets and their Properties – Part 2 Connector: (Level 4) What is a magnetic field? Answer in your own words Lesson Outcomes How I did Targets Task 1: Use abstract ideas to demonstrate interactions between poles using field lines Level 5 Task 2: Explain how it is possible to make a magnet Level 6 Task 3: Use scientific ideas or abstract ideas to explain what happens to metal atoms when you make a magnet Level 7

BIG picture What skills will you be developing this lesson? Literacy Team work Self management Creative thinking Independent enquiry Participation Reflection How is this lesson relevant to every day life? (WRL/CIT)

Magnets and Magnetic Fields The region around a magnet where it has a magnetic effect is called its magnetic field. When a magnetic material is placed in a magnetic field it will experience a force. N S The iron filings feel the effect of the magnetic field and show the direction of the forces in this region.

Shape of a Magnetic Field What is the shape and direction of the lines of force in the magnetic field around a bar magnet? strongest field at poles strongest field at poles N S weakest field further away from poles Where is the magnetic field strongest?

Strength of Magnetic Field Well, we can’t see it for a start, but... However, iron filings are pushed into patterns by a magnetic field. If we sprinkle iron filings on a piece of paper over a magnet we can see... The lines of force are very close together here – the field is very strong. The lines of force are further apart here – the field is weaker. A line of force links one pole of a magnet to the other pole.

Magnetic fields N S

Viewing magnetic fields: N poles together New Information for Task 1 Viewing magnetic fields: N poles together S N N S Bring the two north poles as close to each other as possible and place a piece of paper on top of the magnets. Carefully scatter iron filings onto the paper. Draw the pattern created by the iron filings.

Q1 What do you notice about the pattern of the lines of force in the region between the two north poles? S N N S

Viewing magnetic fields: N and S poles together Bring the north and south poles of two bar magnets together. What happens to the magnets? S N S N Next, put the north and south poles close to each other, without letting them touch, and place a piece of paper on top. Carefully scatter iron filings onto the paper. Draw the pattern created by the iron filings.

Q2 What do you notice about the pattern of the lines of force in the region between the north and south poles? S N S N Q3 How does this pattern compare with the pattern between the two north poles?

Task 1: Answers Attracting

Task 1: Answers Repelling

Task 1: Answers Attracting Repelling

How can I improve on task 2? Task 1: Review Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column. Lesson Outcomes How I did Targets Task 1: Level 5 Met? Partly met? Not met? How can I improve on task 2?

Making a magnet New Information for Task 2 A magnet can be made by magnetizing a material which is attracted to a magnet, e.g. a paper clip. There are three methods that can be used to make a magnet: Stroke a magnet along the paperclip from one end to the other and then starting from the same place, repeat the movement. The more times this is done, the more magnetic the clip becomes. Hold a nail in a magnetic field and hit it with a hammer. Put a magnetic material in a strong magnetic field.

Task 2 For this experiment write the IV, DV, CV How will you make it safe? What apparatus will you use? Draw a results table

Experiment Making a magnet Does an iron nail attract a paper clip? Groups ‘A’ Bang the iron nail with a hammer 50 times and try again , how many paper clips it can attract now ? Groups ‘B’ Rub the iron nail with a bar magnet for a few minutes. Does it attract the paper clip? How many ?

Task 2: (level 6) Task 2: Answer the following questions: Which materials can be turned into magnets? What are the three ways in which magnets can be formed? From what have you seen, which method was the best at making a magnet? What is your evidence for this?

How can I improve on task 2? Task 2: Review Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column. Lesson Outcomes How I did Targets Task 1: Level 5 Met? Partly met? Not met? How can I improve on task 2?

New Information for Task 3 What causes magnetism ? Some metals can become magnetic. They contain ‘domains’ which are like small magnets each with a N and S pole. Normally these are all pointing in a random way, so the magnetic effect of each domain is cancelled out. To magnetise a material these domains must point in one direction.

Hammering an iron nail can also align the magnetic domains.

Task 3: (Level 7) Task 3: Read through the worksheet called ‘8Ja3 What is a Magnet’ Stick into your books. Answer all questions in your books.

How can I improve on task 3? Task 3: Review Go back to your lesson outcome grid and fill out the ‘How I did’ and the ‘Targets’ column. Lesson Outcomes How I did Targets Task 3: Level 7 Met? Partly met? Not met? How can I improve on task 3?

Homework Homework task: Due date: Criteria for level 5: