- Learn the Parts of the Atom
The first step is to learn the parts of an atom so you know how the model should look. Atoms are made of protons, neutrons, and electrons. A simple traditional atom contains an equal number of each type of particle. Helium, for example, is shown using 2 protons, 2 neutrons, and 2 electrons.
The form of an atom is due to the electric charge of its parts. Each proton has one positive charge. Each electron has one negative charge. Each neutron is neutral or carries no electric charge. Like charges repel each other while opposite charges attract each other, so you might expect the protons and electrons to stick to each other. That's not how it works out, because there is a force that holds protons and neutrons together. The electrons are attracted to the core of protons/neutrons, but it's like being in orbit around the Earth. You are attracted to the Earth by gravity, but when you're in orbit, you perpetually fall around the planet rather than down to the surface. Similarly, electrons orbit around the nucleus. Even if they fall toward it, they are moving too fast to 'stick'. Sometimes electrons get enough energy to break free or the nucleus attracts additional electrons. These behaviors are the basis for why chemical reactions occur!
- Find Protons, Neutrons, and Electrons
You can use any materials that you can stick together with sticks, glue, or tape. Here are some ideas:
- ping pong balls
- foam balls
- clay or dough
- paper circles (taped to paper)
- Assemble the Model
The nucleus or core of each atom consists of protons and neutrons. Make the nucleus by sticking protons and neutrons to each other. For a helium nucleus, for example, you would stick 2 protons and 2 neutrons together. The force that holds the particles together is invisible. You can stick them together using glue or whatever is handy.
Electrons orbit around the nucleus. Each electron carries a negative electrical charge that repels other electrons, so most models show the electrons spaced as far apart from each other as possible. Also, the distance of the electrons from the nucleus is organized into "shells" that contain a set number of electrons. The inner shell holds a maximum of two electrons. For a helium atom, place two electrons the same distance from the nucleus, but on opposite sides of it. Here are some materials you could attach the electrons to the nucleus:
- invisible nylon fishing line
- drinking straws
How To Model an Atom of a Particular ElementIf you want to make a model of a particular element, take a look at a periodic table. Every element in the periodic table has an atomic number. For example, hydrogen is element number 1 and carbon is element number 6. The atomic number is the number of protons in an atom of that element. So, you know you need 6 protons to make a model of carbon. To make a carbon atom, make 6 protons, 6 neutrons, and 6 electrons. Bundle the protons and neutrons together to make the nucleus and put the electrons outside the atom. Note that the model gets slightly more complicated when you have more than 2 electrons (if you're trying to model as realistically as possible), because only 2 electrons fit into the inner shell. You can use an electron configuration chart to determine how many electrons to put into the next shell. Carbon has 2 electrons in the inner shell and 4 electrons in the next shell. You could further subdivide the electron shells into their subshells, if you wish. The same process can be used to make models of heavier elements.
Learn MoreWhat Is an Atom?
Overview of Atom Structure
Diagrams of Atoms of the Elements