Name: _____________________________
Building an Atom
1. Go to the link below:
https://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html
Click on the atom box
2. On the bottom of the page are three buckets of subatomic particles (protons, neutrons, and
electrons). Click a drag the particles to the center of the atom to add them.
a. Which subatomic particle changes the chemical element name?
b. Where are these located in the atom?
c. Create the chemical: Beryllium. Add electrons to the atom. How many electrons can fit
on the inner ring?
d. How many can fit on the outer ring?
3. Click the reset button on the right and click on the net charge box. Add each subatomic particle
to the atom.
a. How do protons change the charge of an atom?
b. How do neutrons change the charge of an atom?
c. How do electrons change the charge of an atom?
4. Add protons until you have carbon.
a. How many protons are in the atom?
b. How many electrons would you need to achieve a net charge of 0?
5. Click reset. Add protons until you have lithium. Check the ‘stable/unstable’ box on the bottom
right.
a. Is this atom stable?
b. Try to make lithium a stable atom. What did you do to achieve stability?