Inside the Atom

Rutherford and the nucleus

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Atoms are mostly empty space around a tiny, dense nucleus (Rutherford).
• Z = protons (decides the element), A = protons + neutrons. Isotopes differ in neutron number.
• The strong nuclear force holds the nucleus together against electric repulsion.

Steps

1. Bullets and tissue paper
2. Protons, neutrons, isotopes
3. Count the neutrons
4. What holds it together?
5. Rutherford’s surprise
6. How small is a nucleus?