Answer:
An atom or, to be more specific, a helium atom.
Step-by-step explanation:
This is a model of an atom. You can tell by the nucleus made only out of neutrons (the balls with no + or - sign) and protons (the balls with the + sign) and by the electrons (the balls with the - sign) circling around the nucleus.
This is a model of not just any atom, but a helium atom. An atom is defined by it's number of protons. For example, an atom with 1 proton is always hydrogen and an atom with 6 protons is always carbon. As you can see, this model has 2 protons. Any atom with 2 protons is a helium atom. This is a model of a helium atom.
I hope this helps. Feel free to ask my any questions if you are confused. Happy studying. Enjoy your thanksgiving. :)