Experiment 1: The Atom
Everything around us is made of matter: this piece of paper, the chair you
are sitting on, even the air we breathe. All matter is made up of tiny
particles called atoms.
The Atom
The atom is made of three types of even smaller particles:
1. Electron: negative charge
2. Proton: positive charge
3. Neutron: no charge, neutral
We can see evidence of these invisible little particles in our everyday lives.
Electricity, for example, is flowing electrons.
The Nucleus
Protons and neutrons make up the center of an atom. This center is called
the nucleus. These protons and neutrons are held together really tightly by
something scientists call the strong force.
Electrons are always found whizzing around the nucleus, much like the earth
orbits the sun.
Elements
Different elements are defined by the number of protons they have. All
atoms with the same number of protons are the same element. The smallest
atom, Hydrogen, has one proton. The second smallest element, Helium, has
two protons. The heaviest element that has been discovered so far is called
Ununquadium, and it has 114 protons. On the next page is the Periodic
Table, which lists all of the known elements. Each box is for one element,
which has a special symbol. The number above each symbol in each box,
called the atomic number, is the number of protons in each atom. Take
some time to look at the Periodic Table with your mentor.
Making Your Own Atom
Materials:
 1 piece of paper
 1 brownie = strong force
 2 Candy Corns = protons
 2 Marshmallows = neutrons
 2 Red Hots = electrons
 2 Twizzler strands = electron orbit
Procedure:
1. Place the piece of paper on your desk.
2. Put the brownie in the center of your paper. Your brownie
will make the marshmallows and candy corns stick together
just like the strong force makes protons and neutrons stick
together.
3. Stick one “proton” into your brownie.
4. Now lay the Twizzlers around your brownie in a circle, to
represent the electron orbits.
5. Stick one “electron” onto the orbit.
At this point you have made a model of the simplest atom. Do you
remember what it is?
6. Now add one “proton” and two “neutrons” to the brownie.
7. Add one “electron” to the Twizzler orbit.
Now you have made the second simplest element, Helium. If you
still have time, get another candy corn, marshmallow, and red hot
and add them to your atom. Look at the periodic table. Can you
figure out which element you made? Talk about it with your
mentor.
Are you hungry? Can you make your atom disappear?
Review Questions
1. What is the scientific name for the center of an atom?
2. Where are electrons located in an atom?
3. What is the charge of a proton? A neutron?
5. Look at your periodic table. Which element has 8 protons? Which
element has 79 protons?
4. What is the element below?