Atomic Nucleus

Physics:	The Atom, Parts of the Atom
Grade Range:	Elementary School, Middle School, High School
Format:	Hands-on

This demonstration is an engaging approach on talking about the parts of the atom. With younger students you can discuss the basics of the parts of the atom and how elements are made, while with older students you can talk more about the charge of the atom, Anions and Cations, and isotopes!

Materials

• Velcro atom
• Million dot book (optional)
• Velcro electrons (optional)

Safety Precautions

Please see the Other Demonstration Hazards and Safety Precautions section on the Demonstration Safety page.

Demonstration

Preparation: Make sure the velcro atom is disassembled before beginning the demonstration.

1. Show the two parts of the velcro atom to the students, identifying the protons and neutrons. (Optional) Include the electrons.
2. (Optional) Show the million dot book, and explain the small size of the atom.
3. Have the students try to assemble an atom with just the neutrons. When they show they cannot, explain why.
4. Have the students start building an atom with the protons and neutrons. (Optional) Have them add electrons in for each proton they put in.

Why This Works

All of matter is composed of Atoms. Atoms are very small building blocks, smaller than a billionth of a meter, or a nanometer. To get how small this is you can reference the million dot book which, as the title says, has a million dots inside of it. You would need a thousand of those books to get to one billion dots, and even at that point you would have to split each dot into three pieces to get to the scale of atoms!

An atom's nucleus is composed of two things: Protons and Neutrons. Protons have a positive charge, and the number of protons in an atom determines what element that atom is. If we use only one proton, that would be hydrogen. If we use six, that makes it carbon. However, it is really hard to get six protons to stick together; protons have a positive charge, and like charges repel. That's where neutrons come into play; neutrons have a neutral charge, so they can connect to protons. They help to keep those protons together for bigger elements. We can adjust the number of neutrons that are in an element, which changes how the element interacts with other elements. Each type of an element with a different number of neutrons is known as an isotope, and some isotopes are more stable than others. For example, Carbon-12 is stable, and is the carbon we usually see, with six protons and six neutrons. Carbon-13 has one extra neutron, and is what we use for Carbon Dating, a method to figure out how old something is!

Electrons are smaller than protons and neutrons, and are not in the atom itself. They have a negative charge, and float around the atom because of the positive charge on the protons. If an atom doesn't have an equal number of protons and electrons, then it will have a charge, and we would call it an ion. If it lacks electrons, it has a positive charge, and is called a cation. If it has extra electrons, it has a negative charge, and is called an anion.

Additional Information

• This demonstration is a part of the Nuclear Physics Show.