If a nucleus is full of positively charged protons, why doesn’t it fly apart?

In my physical science class this week, I realized the textbook was introducing the structure of the atom and positive and negative charges, but not answering addressing the clear question that follows the presented information is “what the heck keeps all those protons together in the nucleus?” The book does get around to the nuclear forces, but not until many chapters later when it presents forces.

This gap in reasoning seems consistent in many introductory chemistry/physical science books. In an attempt to bridge this gap, I have written a brief introduction to the four fundamental forces. My target audience is our 9th grade introductory physical science class, but it might also be useful in higher or lower grades.

• Why does a nucleus that is full of positively charged particles not fly apart (Word format)
• Why does a nucleus that is full of positively charged particles not fly apart (PDF format)

Since my school has moved to 1:1 iPads, I formatted this document to fit well on a landscape mode (“hamburger”) iPad: 8.5″ wide by 5.5″ tall. If you want to print it, you can use a PDF reader to print two on a page, or take the Word document and edit it to your heart’s content.