Fremont Magnet Elementary

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Introduction to Atoms

a. During chemical reactions, the atoms in the reactants rearrange to form products with different properties.
b. All matter is made of atoms, which may combine to form molecules.
e. Scientists have developed instruments that can create images of atoms and molecules showing that they are discrete and often occur in well ordered arrays.


1. Physical & Chemical Changes Review

Last week you learned matter can change- 
  • Physical Changes are when it changes the way it looks, but it doesn't change the matter.
    Water can freeze and become a solid ice cube, but it is still water and can be changed back.


  • Chemical Changes are when the matter changes and becomes something new.  You can't easily reverse the process and get the same thing.
    Baking a cake


Which of these is a physical change?

  toasted bread
  burnt  wood
chopped carrots

Which of these is an example of a chemical change?

  An ice cube that has melted
  a fried egg
melted wax from a candle

A chemical change is ______


2. What is an atom?

You know that everything is made of matter, and atoms are what matter is made from. 

Atoms are the "building blocks" that make up EVERYTHING! 

Atoms are very, very small.

Look at these oxygen atoms

Atoms are usually lined up in an orderly way.


3. An atom is very small, so how do scientists know about them?

Click on Strange Matter and zoom in to see the atoms in a soda can.

Click on Learn More About This Small World.

Strange Matter

You can use a virtual electron microscope by clicking here.

4. If everything is made of atoms, why doesn't everything look the same?

There are different kinds of atoms.  When 2 or more atoms combine and join together they create a molecule.   Molecules can be made from the same kind of atoms or combinations of different atoms.

All molecules are made from atoms, but they look different because of the way they are put together. 

Look at the pictures below.  These are models of different molecules.  They all are made of atoms, but they are put together differently.

Carbon Dioxide Glucose (sugar) Water

5. Chemical Changes and Atoms

You can cause molecules to change the way they are put together by making a chemical change. 

Example: When you burn a log in the fireplace, the molecules of the log change and become ash.

6. Now Try This

Try making carbon, iron and silicon molecules change by -

heating, beating and treating them. 



Draw a picture or write about what you have learned.


more molecules to look at



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