Experiment 1: the Atom

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?