Applied Science - Physics (3A)
Pre Lab 

   
OBJECTIVES:
  • Exploring magnetism.
  • Comparing how a magnet repels and attracts.

VOCABULARY:

  • attract
  • magnet
  • magnetism
  • negative
  • positive
  • repel
MATERIALS:

Students discover the three naturally magnetic elements.

BACKGROUND:

Physics is the study of physical events on Earth and in the Universe. It is an attempt to explain why and how certain events occur. Physics occurs whether we understand it or not. For instance, when you pick up a book and drop it, the force of gravity pulls it toward the Earth. (Illustrate this with your students.) How does this happen? In part, this is still a mystery because we know that larger objects attract smaller objects. Exactly how they attract is not known. Whether you know why the book will fall or not, the book will still fall.

There are 4 major ways in which matter interacts on our planet. There are strong interactions and weak interactions, which involve the use ways atoms operate. Gravity is another interaction, which is mysterious, because we donít feel a force, but its impact is widespread. Electromagnetism is also an interaction, whose mysteries have been realized in the early part of the 1900's.


Electricity and magnetism are related and are the components of electromagnetism. Light is a subset of the electromagnetic wave spectrum. The electromagnetic wave spectrum also includes radio waves, microwaves, ultra violet rays, x-rays, and gamma rays. Magnets exhibit both attractive and repulsive forces. North attracts south, north repels north, and south repels south.

Magnetism and electricity are related.  Both magnetism and  electricity have opposites.  In magnets north repels north and south repels south, but north attracts south. In electricity  when you hook up  positive and negative electrodes can the electrons flow creating current electricity. 

PROCEDURE:

  1. Discuss with students that the study of "physics" includes topics such as gravity, electricity, magnetism, light and friction. The next several units will concentrate on explaining electricity and magnetism. In previous labs, students have experienced both phenomena. The third grade is when students will begin understanding why these phenomena occur.
      
  2. Go over the structure of an atom with students. Remember all matter is made up of elements, which are made up of atoms. Go over electrons, protons, and neutrons. On the picture below point out that the nucleus is the center of the atom with the neutrons (neutral) and protons (positive charge) are located. The electrons (negative charge) are revolving around the nucleus. Electrons are important in understanding electricity and magnetism

  1. Show students the periodic table of the elements. Remember all elements are made up of atoms. Quiz them on their knowledge. For instance, "The gas we need to live is called ______(students answer oxygen. What is the symbol?"

    What is salt made up of? Sodium (Na) and Chlorine (Cl)
    What are several metals? Iron (Fe), Nickel (Ni)
    What metal is a character from the Wizard of Oz made of? Tin (Sn)
    What are rings made of? Gold (Au), Silver (Ag)
      
  2. Ask students how many elements are naturally magnetic. The only three naturally magnetic elements are nickel, cobalt, and iron.
      
    Notice that the three of them are very close on the Periodic Table. The periodic table is designed so that elements with similar properties are near each other. Iron is the weakest of all the elements; nickel and cobalt are the strongest and keep their magnetism longer. The magnets we use in this program are called ALNICO, which stands for aluminum, nickel and cobalt.
      
  3. Use the magnets to illustrate the basic principles of magnetism, like repel and attract. If students are unfamiliar with magnets, they may need to play with the magnets before the lab.
  4. Either read or have students read Electrons and the Hairy Monster.  This book allows  students to look at the similarities of magnetism and electricity.   You may want to read the book as a class to make sure that students are following the connection.  Key concept is both electricity and magnetism have opposites. 

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