If the F is on your transcript then you should address it. At the same time, I wouldn’t write your personal statement about it. If on the application there is a section for additional information, that is where I would put it. I would be honest about it and how you learned from your mistake. It is important to let adcoms know you would never do it again, and make sure you have strong LORs from your professors. Do not be defensive or give excuses. Good luck.